The figure shows the amount of water in two rectangular tanks, B and C, at first. Andy poured
15 of the water from B into C to fill it to the top, without overflowing.
- How much water was there in Tank B at first?
- Andy then poured all the water from Tank C into Tank B. 1800 cm3 of water overflowed from Tank B. What was the height of Tank B?
(a)
Volume of water to fill Tank C
= 15 x 12 x 12
= 2160 cm
3
15 of volume of water in Tank B at first = 2160 cm
3
55 of volume of water in Tank B at first = 5 x 2160 = 10800 cm
3 Volume of water in Tank B at first = 10800 cm
3 Volume of water in Tank C at first
= 15 x 12 x 15
= 2700 cm
3 Total volume of water in Tank B and Tank C
= 10800 + 2700
= 13500 cm
3 Final volume of water in Tank B after 1800 cm
3 of water overflowed
= 13500 - 1800
= 11700 cm
3 Base area of Tank B
= 20 x 15
= 300 cm
2 Height of Tank B
= 11700 ÷ 300
= 39 cm
Answer(s): (a) 10800 cm
2 ; (b) 39 cm