Question

5,6,7,8,9,10题，都是数学，帮忙做一下，急求

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Answer 1

5(a) volume of cylinder=(pai)(10)square(21) =2100pai
volume of ice-cream= 4/3(pai)(2.1)cube =12.348 pai
2100pai/12.348 pai =170 scoops of ice cream
(b) 170 x 86 =14620 (i don't know what currency is that)

6(a) radius of choc =7.5/2 =3.75
volume of choc= 4/3(pai)(3.75)cube =70.3125pai / 220.89
(b) volume of box=7.5 x 7.5 x 7.5 =421.875
amount of space = 421.875 - 220.89
= 200.985

7(a) volume of balloon=4/3(pai)(0.25)cube =0.06544(metre cube)
(b) 0.06544 x 7.02 = $0.459/$0.46

8 volume of ball with radius of 10cm =4/3(pai)(10)cube
=4188.79
volume of ball with radius of 7.5cm = 4/3(pai)(7.5)cube
=1767.15
how much rubber can save= 4188.79 - 1767.15
= 2421.64

9 volume of sphere with radius of 5 = 4/3(pai)(5)cube
=523.6
volume of sphere with radius of 6.5 =4/3(pai)(6.5)cube
=1150.35
1150.35-523.6 =626.75 , the student needs 626.75 cmcube of clay

10 volume of ball= 4/3(pai)(11.14)cube
= 5790.87
volume of box = 22.28 x 22.28 x 22.28
=11059.76
volume of space =11059.76 - 5790.87
= 5268.89
percentage of space =5268.89/11059.76 x 100
= 47.64%

That's the end of the solution, pls be notice that my pai is not 22/7 or 3.142 ,i juz press straight fr the calculator......anyway, hope you can understand my solution!

Answer 2

5.1 (10*10*派*21)/(4/3)*派*4.2*4.2*4.2约等于170
5.2 170*86=14620
6.1 4/3*3.75*3.75*3.75*派约等于220.89
6.2 7.5*7.5*7.5-220.89=220.98
7.1 4/3*0.25*0.25*0.25*派约等于0.065
7.2 7.02*0.065=0.4563
8 4/3*派*（10*10*10-7.5*7.5*7.5）约等于2421，64
9 4/3*派*(6.5*6.5*6.5-5*5*5)约等于626.75
10 1-（4/3*11.14*11.14*11.14*派）/22.28*22.28*22.28约等于47.64%

Answer 3

5、（a）170 (3.14x10^2*21)/(4/3*3.14*2.1^3)
（b）170x86

6、（a）1/2*7.5^3
（b）1/2*7.5^3