The figure shows the amount of water in two rectangular tanks, L and M, at first. Paul poured ¹₅ of the water from L into M to fill it to the top, without overflowing.

1. How much water was there in Tank L at first?
2. Paul then poured all the water from Tank M into Tank L. 6948 cm³ of water overflowed from Tank L. What was the height of Tank L?

(a)
Volume of water to fill Tank M
= 18 x 14 x 15
= 3780 cm<sup>3

1</sup>₅ of volume of water in Tank L at first = 3780 cm^3  
5₅ of volume of water in Tank L at first = 5 x 3780 = 18900 cm³

Volume of water in Tank L at first = 18900 cm³

Volume of water in Tank M at first
= 18 x 14 x 17
= 4284 cm³

Total volume of water in Tank L and Tank M 
= 18900 + 4284
= 23184 cm³

Final volume of water in Tank L after 6948 cm³ of water overflowed
= 23184 - 6948
= 16236 cm³

Base area of Tank L
= 22 x 18
= 396 cm²

Height of Tank L
= 16236 ÷ 396 
= 41 cm

Answer(s): (a) 18900 cm² ; (b) 41 cm