Maths 的功課 (F.1 - F.2)

2008-08-30 11:18 pm
1. The figure shows a prism whose base is a parallelogram.
It the total surface area is 3284cm^2,
find its volume.

2. The bigger square in the figure is made up of4identical rectangles and a smaller squares are 49 cm^2 and 4cm^2.
Find the width of one rectanfle.

3. How many pairs of rabbitswill there be after 6 months,if each pair produces a new pair each month,and each new pair bedins to bear young two months after its own birth?
更新1:

1. The height of the parallelogram is 12cm and the base of the parallelogram is 16cm.

更新2:

1. [img]http://img172.imageshack.us/img172/4034/cimg4614cn3.jpg[/img] 2. [img]http://img301.imageshack.us/img301/8876/cimg4615rb4.jpg[/img] 3. [img]http://img172.imageshack.us/img172/2461/cimg4618dl2.jpg[/img]

回答 (2)

2008-09-09 2:26 am
✔ 最佳答案
1.Let the height of the prism be y

192+192+13y+13y+16y+16y=3284
26y+32y=2900
58y=2900
y=50

Volume of the prism:

12x16x50
=9600cm^3

Ans:9600cm^3

2. (I'm not sure what you're asking about, so I take 49cm^2 as the area of the bigger square and 4cm^2 as the area of the smaller square)

Area of the bigger square:
=49cm^2

Length of the side of the bigger square:
=7cm

Length of the side of the smaller square:
=2cm

Let the width of the rectangles be y:

y+2+y=7
2y=5
y=2.5

Ans: 2.5cm

3.
at the beginning: 1 pair
after 1 month : 2 pairs
after 2 months : 3 pairs
after 3 months : 5 pairs
after 4 months : 8 pairs
after 5 months : 12 pairs
after 6 months : 17 pairs

Ans:17 pairs of rabbits
2008-08-31 12:30 am
3. 4 pairs of rabbits


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