帮孩子补数学，可是让我很郁闷。本以为自己当年理科还可以，但现在连题都搞不明白。
1.When 7200 is resolved into prime factors, the number of 2"s will be: a. 3 b.4. c .5 d. 6
2 . A student counts all the digits used to number the pages of a book. If 615 digits were used, starting at page 1 , the number of pages in the book will be: a 615, b 241 c 328 d none of above.
望不惜赐教，多谢。
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1.c
2.d
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要有解题意理解和解题过程
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第一题大概是问7200能被2 整除多少次。
第二题，我也没看懂啊。
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几年级的题目
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prime factors means质因数。this is year 5's question.
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2 . A student counts all the digits used to number the pages of a book. If 615 digits were used, starting at page 1 , the number of pages in the book will be: a 615, b 241 c 328 d none of above.
1。 page 1-9 9 digits
2. page 10-99 180 digits
so total 189 digits, 615-189=426 left
3. from page 100, one page 3 digits 426/3=142 page
4. 99+142=241
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补习班的作业？:)
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615 digit指用了615个数字,
1-9 每页都用了1个数字,共9个.
10-99 每页都是2位数表示页数 10, 11,...99, 共用了(99-10+1)*2=180个数字
还剩下615-9-180=426个数字
从100 页开始每页都是3位数 , 426/3=142, 所以100+142-1=241 即100-241有142个三位数.
LZ,这样解释ok?
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第一题可以理解为因式分解,几个因子为2
7200=8x900=2x2x2x(2x2x3x3x5x5)
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谢谢ls们的分享
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哥！我比你先过这一关，继续努力吧，题不够我这里有大把随时来拿。
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2's是什么意思？
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2's 就是多个2, 2 的复数形式,这里用2's表示.
比如3个3, 英文会写成 3 "3"s
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多谢，明天加分.两道都因为没看懂题意
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2's 其实个人感觉是2s的笔误,或者应该是 "2"s更恰当
上次看到文章里提到澳洲人在这个复数的写法上很多错误,喜欢加 单引号'
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我知道是质因数，只不过解释的白话了一点，一个意思。第二题看了大家的解释才明白是什么意思，看来不是数学不好，是英语不好，哈哈，共勉。
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看了大家的帮助，真是无地自容。建议教育部门以后用中文出题。
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第二题英文看大不懂，ls各位解释之后中文看得也是似懂非懂。真难。
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记得当时是这么做数学题
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包含和排除1. 一天下午,有15个小朋友在操场上打球,有的人打足球,有的人打篮球,每人至少打一种球,
踢足球有12人,,打篮球有8 人,
2 四(一)班学生完成作业的情况是,: 每人至少完成了语文,数学中的一门作业,完成语文作业的有40人,完成数学作业的有36人,语文数学作业都完成有28人,这个班学生有多少人?
(答案48)
3 某班50 名学生每人至少订一种报纸,订(少年报)的有33人,订(小学生报)的有碍29人,两种都订的有多少人? 答案 12
4四(1) 班有48人,在6.1儿童节庆祝活动中,参加运动会体育比赛项目的35确人,参加文艺节目演出的有28人,每人至少参加一个项目(1) 体育比赛和文艺演出都参加的有多少人?
(2) 只参加体育比赛的有多少人, 答案 15 , 20
5 如图 边长是6厘米和边长是4 厘米的两个正方形纸片放在桌上,它们所盖住的面积有多少平方厘米 答案 46
6 某班有50名学生,其中23人参加了数学竞赛,15 人参加了作文竞赛, 有5 人既参加了数学竞赛又参加了作文竞赛,那么(1)只参加数学竞赛的有多少人? (2) 没有参加竞赛的共有多少人? 答案 18 和 17
7 五,三班有56人,在田径运动会上有36 人参加竞赛,有碍30 人参加田赛,这两种都没参加的有18 人,两种都参加的有几人? 答案 28
8 全班40 名同学排成一行做课间操,小红排在顺数第28把手名,小华排在倒数第23 名,那么小红和小华之间有几名同学?部答案 9
9 有48 人参加测验,答对第一题的有35 人,答对第2 题的有 23 人,两题都答对的有15 人,问: 有几人两题都没答对? 答案 5
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100 mini test--- area and volume
*1.11 Three cube X, Y and Z are shown in the diagram. The lengths of the sides of cube Y and twice those of cube X and the lengths of the sides of cube Z are twice those of cube Y. If the volume of cube X is 27 cm3, find the volume of cube Z in cm3 ( PIC)
A 144 B 216 C 1728 D 288
1.12 if the surface area of cube Z is 384 cm2,
find the surface area of cube X in cm2
**2.5 a student has 6 cubes each of side 1cm, the student arranges them in two different ways as shown in the diagram. What would be the difference in the surface area of the two configurations?
PIC
A 26 B 24 C 0 D 2
2.6 a box has a rectangular base measuring 8m by 6m. what must its height be if its volume is 72m3? A 2m B 2.5m C 3m D 1.5m
*4.10 what fraction of the rectangle the diagram has been shaded? PIC
a 1/3 b 2/5 c 1/2 D 7/15
4.11 find the square root of the sum of the squares of 5 and 12
A 17 B 13 c 169 D 60
**5.5 a box is 12cm ling, 15cm wide and 50cm deep. Its volume in litre must be
A 18 B 9 C 9000 D none of these
5.7 the diagram shows a cylindrical piece of wood. Two points A and B are marked of opposite sides of the cylinder as shown, a student uses a saw to make a straight cut through the wood, passing through A and B. the cross-section that will then be exposed will be PIC
A circular B triangular
C rectangular D oval
***6,1 in which of the following quadrilaterals are all the angles equal?
A square B trapezium C parallelogram D kite
***6.8 the rectangle in the diagram is 16cm ling and 6 cm wide, the area of the shaded portion is
A 96cm2 B 44cm2
C 48cm 2 D 22cm2 Pic
6.9 all the diagonals of a pentagon are drawn, what fraction of the total number of sides and diagonals is the number of diagonals?
A 4/5 B 5/9 C 4/9 D 1/2
**8.2 the surface area of a cube is 150cm 2, its volume, in cm3, would be:
A 125 B 216 C 1000 D 512
8.10 the diagram shows a figure made up of identical squares PIC
The percentage of the figure which is unshaded is
A 331/3 B 66 2/3 C 58 1/3 D 41 2/3
***9.8 a tank is made in the shape of a rectangular prism, measuring 12cm by 16cm by 10cm , it is full of water. A small rectangular prism measuring 2cm by 3cm by 4cm is fropped into the full tank, the amount of water which be
A 24cm3 B 1920cm3 C 1896cm3 D 12cm3
*10. 2 two circles fit exactly into a rectangle. The radius of one of the circles is 6cm (PIC)
A 144 B 288 C 72 D 196
**11.3 how many squares of any size are there in the diagram? PIC
A 2 B 4 C 6 D 8
11.4 if the area of the figure is 294cm2, then the perimeter of the figure, in centimeres , will be
A 280 B 70 C 42 D 490
11.6 four fifths of a glass jar is filled with water, suzy put a red mark on the glass, level with the surface of the water, she then turned the jar upside down and put another red mark on the glass, level with the surface of the wate, what fraction of the jar’s volume would lie between the two red marks?
A 4/5 B 3/5 C 1/2 D 1/3
***12.1 express 0.875ml as a fraction of 2L
12.3 the large rectangle has been divided into 4 smaller rectangles, the areas of the smaller rectangles are shown on the diagram, the perimeter of the large rectangle is (PIC)
A 18 B 36
C 24 D 32
12.5 a container in the shape of rectangular prism, measures 16cm by 14cm by 25cm , how many litres of fluid would it hold
A 5.6 B 5600 C 2800 D 2.8 Remember 1ml = 1 cubic centimeter
12.6 a paddock is being used for a football field , the length and breadth of the paddock are 100m by 80m respectively, find the area of the paddock in hectares. PIC
A 80 B 0.8 C 800 D 8000
*13.5 as a project, we divided the courtyard outside the principal’s office into 16 squares, the courtyard we itself a square, with a side of 20m, we had to paint each of the small squares a different colour, during a week, we painted 5 of the small squares, as shown in the diagram, what area, in square metres, was left to paint? PIC
A 125 B 325 C 275 D 375
13.8 the perimeter of a rectangle is 26cm and its area is 40cm2, the difference in the lengths of the sides must be:
A 3 B 5 C 8 D 9
13.12 the surface area of a cube is 150cm2, the sum of th elengths of its edges, in centimeters will be: PIC
A 30 B 60
C 90 D 45
Remember cm3=cubic centimeres
**14.1 consider the blocks in the diagram:
PIC
A girl stands at the point marked a and looks at the blocks , which of the following would best represent what she would see? PIC
14.6 you can buy honey in different sized jars , which of the following would represent the best value?
A 1L costing $12.90 B 500ml costing $6
C 200ml costing $2.20 D 6l costing $78
***15.9 refer to diagram below, it is not drawn to scale , all measurements are in centimetres and all angles are right angles. PIC
the perimeter of the figure will be
A 29cm B 30cm
C 40cm D there is not enough information to tell
15.10 The area of the figure will be: A 76cm2 B 20cm2 C 1920cm2 D there is not enough information to tell
**17.3 the length of a rectangular prism is 3 times its breadth and the height of the prism is twice its breadth, if its volume is 384, then its height must be:
A 12 B 16 C 8 D 6
17.5 the rectangle shown in the diagram has been divided into 16 unequal parts, what fraction of the rectangle has been shaded?
A 2/3 B 39/80 C 1/2 d 3/5 PIC
17.6 Solm draws three squares, the length of the side of the largest square is twice the length of the side of the next largest square. And the length of the side of the smallest square is one quarter the length of the side of the largest square, solm makes the side of the largest square equal to 32 cm and draws the square as shown in the diagram, what would be the size of the shaded area in square centimeters?
A 224 B 324 C 192 D 256 PIC
***18.2 the quadrant of a circle has an area of 24cm2 , half of the area of the circle would be;
A 24cm 2 B 48cm2 C 96cm2 D there is not enough information to tell
18.5 find the area of the triangle in the diagram, measurements are in metres. PIC
A 32m2 B 64m2 C 16m2 D 24
18.9 A ladle holds 625ml of liquid , how many times would the ladle have to be filled in order to empty a 35L tank
A 54 B 48 c 56 D 60
**20.3 we designed a new flag, it had 3 small rectangles, each of the same size and each of a different colour, arranged as shown in the diagram, the flag measured 120cm by 48cm , the area of one of the small, shaded rectangles in cm2 would be PIC
A 320 B 480 C 600 D 640
20.5 a group of squares of side 2cm are placed on a table as shown in the diagram, the perimeter of the figure is: PIC
A 16 cm B 14cm C 32cm D 36cm
20.6. the area of the figure would be:
A 28cm 2 B 7cm 2 C 24cm 2 D 14cm2
7 the area of rectangle whose sides are 4cm and 16cm equals the area of a square, the perimeter of the square must be:
A 64cm B 32cm C 8cm D none of these
20.11 all the angles in the figure shown in the diagram are right angles, all the measurements are in centimeters . PIC
The perimeter of the figure is
A 30 B 60 C 42
D there is not enough information to tell
20.12 if the lengths of each part of the step-like part of the figure are equal, what is the area of the figure
A 162cm2 B 158cm2 C 297cm2 D 189cm2
*21,2 change 5.2ha to square metres
A 520 000 B 52000 C 5200 D 520
12.8 the net of a cone shown in the diagram , the length op is 8cm and the circumference of the circle is 12cm, the length of the are PRQ is PIC
A 8cm B 12cm C 20cm
D there is not enough information to tell
21．5 which of the following is the only one to be solid and have identical faces?
A equilateral triangle B tetrahedron C rectangular pyramid D cone
21.8 the net of a cone is shown in th ediagram. The length OP is 8cm and the circumference of the circle is 12cm. The length of the are PRQ is : PIC
A 8cm B 12cm C 20m D there is not enough information to tell
21.10 A bucket holds a maximum of 12.45 L . If it contains 7.88L how much more can be added to it? A 3.57L B 4.57L C 4.67L D 3.67L
*22.4 Pick a circle in the top row. Now pick another circle, in the third row, directly underneath the first circle. If the distance between the centres of these two circles is 20cm. find the number of square centimeters in the area of the square: PIC
A 400 B 625 C 900 D 725
22.9 one gram of water has a volume of 1 cubic centimeter. What would be the weight of 2.5L
A 250g B 25kg C 2.5kg D 2500kg
22.10 A square has a perimeter of 64cm . A rectangle has a length of 24cm . If their perimeters are equal, then how wide is the rectangle?
A 12cm B 8cm C 4cm D 24cm
22.11 squares are drawn on each of the sides of the rectangle. The total area, in square centimeters, of the rectangle and the four squares would be:
A 2X+2X8 + 8x24 B 242 +82+8x24 C 2x242+2 x82 D 2x242+2x82+8x24
22.12 the perimeter of an isosceles triangle whose base is 1.6cm is 10.2cm, find the length of one of the equal sides:
A 4.3cm B 8.6cm C 5.9cm D 8cm
**23.4 A quadrant of a circle of area 320cm2 is divided into 16 equal parts. The area of three of these parts would be:
A 45cm2 B 15cm 2 C 5cm2 D 30cm2
23.5 the first rectangle I drew measured 3 cm by 5cm. In the second one I drew I doubled the length and breadth. How many times more area does the second rectangle have compared with the first? A 2 B 4 C 30 D More than 30
23.11 a child builds a cardboard model of the Arc de TRiomphe in Paris ,from the front it looks like that shown in the diagram. The model is symmetrical and all its angles are right anglees.
The perimeter of the front of the model is
A 84cm B 68cm C 62cm D there is not enough info to tell
12 the area of the front of the model is:
A 200cm 2 b 264cm 2 c 80cm2 D there is not enough info to tell
***24.7 the cube in the diagram has a side of 3cm. find the surface area of this cube in cm2
Pic A 27 B 54
C 108 D 36
24.8 from this cube, another cube is cut. This cube has a side equal to 2cm. What would be the surface area of the remaining solid? Answer in cm2 PIC
A 30 b 36
C 54 D 96
24,9 the volume of this new solid in cm3 will be:
A 19 B 26 C 24 D 2
*25.1 find the square root of the sum of eight square and fifteen square:ＰＩＣ
Ａ ２３ Ｂ ２８９
Ｃ １７ Ｄ １５
25.2 the large rectangle has been divided into 4 smaller rectangles. The areas of the smaller rectangles are shown on the diagram. The perimeter of the large rectangle is PIC
A 60 B 56
C 64 D 30
25.4 how many axes of symmetry would a regular hexagon have? PIC
a 3 B 6 C 9 D 12
25.9 the window of our classroom is square. We found that it let in too much sun. so we covered part of it with brown paper. What fraction of the original window has been covered? PIC
A 1/4 B 1/3
C 1/2 D 3/4
25.10 if you measured the area of this page , it would be closest to:
A 60cm2 B 600cm 2 c 6000cm2 D 60mm2
25.11 the circumference of circle is 3.1times the diameter. A car has a wheel of diameter 90cm . its circumference would then be:
A 27.9 B 279cm C 29cm D 290cm
25.12 as the car moves, the wheel of the car revolves 300 times, how far does it travel? Answer in meters A 837m B 1075m C 2595m D none of these
**26.10 the circumference of wheel is 400cm , the wheel revolves 3 times every 5 seconds. The speed in metres per second of a point on the edge of the wheel would be
A 24 B 240 C 2.4 D 7.2
26.11 a piece of wire 48cm long is cut into six equal parts and welded together to form the shape shown in the diagram, find the area of this shape in square centimeters PIC
A 24 B 36 C 48 Ｄ ６４
26.12 an office has a huge fish tank in the foyer. The tank measures 5m by 2m by 3m, how many litre of water will it hold if it is filled to the brim?
A 30 B 3000 Ｃ ３００００ D 300 0000
***27.6 four students each made a statement about quadrilaterals, which statement is correct?
A first sudent A kite has 2 axes of symmetry
B second student the diagonals of a trapezium are perpendicular
C third student the angles of a paralleoogram add to 1800
D fourth student A parallelogram has no axis of symmetry
27.7 which of the following quadrilaterals has three obtuse angles
PIC
27.8 a rectangle has an area of 240ha, if one of its sides is 2km, find the length of the other side
A 2.4km B 24km C１２ｋｍ Ｄ １．２ｋｍ
*28.8 which of the following areas would measure approximately 1 hectare?
A an average backyard B two football fields C a city block D a school quadrangle
28.10-11 a quadrilateral has sides equal to 304, 5.6, 4.8 and 6.2cm
10 the perimeter of the quadrilateral is
A 20cm B 14,8cm C 16cm D 18.6cm
11 what difference between the average of the larger two sides and the average of the smaller two sides A 3.6cm B 2cm C 1.8cm D 1cm
**29. 4 a room measures 6m by 8m by 3m high, it has 2 doors each measuring 1m by 2,5m
4 the surface area of the walls and ceiling og th eroom would be
A 235m2 B 240m2 C 127m2 D 129.5,m2
5 the volume of the room in litre would be
A 144 B 14400 c 0.144 D 1440000
***30。9 which solid could be formed using all of the shapes in the diagram ?PIC
A triangular pyramid B cube C rectangular prism d triangular prism
30.10 a rectangular piece of paper measures 24cm by 30cm , it is cut into 3 parts by two cuts parallel to the shorter side of the rectangle. If you found the sum of th perimeters of these three parts and subtracted the perimeter of the original piece of paper, you would get:
A 96 B 80 C 48 d there is not enough info to tell
11 repeat question 33 given that the two cuts are made parallel to the longer side of the original rectangle
A 60 B 120 C 148 D 90
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打这么多字， 真是辛苦了。请问有答案吗？准备给孩子做做。
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不好意思当时整理题目时候没留答案，我还有正比反正，扩大与缩小，速度与时间等小学数学题。
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天啊， 这要让我做一遍，把答案做出来， 再给孩子做，难度太大了。
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我要去上补习班了。几乎都忘了。
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不用都做，重要是过程，能理想并能做到举一反三就可以了。
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我晕
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我们都过来了，回头一望也就这样，至少我可以用方程式同客人结帐了。
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