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

1. How much water was there in Tank Y at first?
2. Bryan then poured all the water from Tank Z into Tank Y. 11001 cm³ of water overflowed from Tank Y. What was the height of Tank Y?

(a)
Volume of water to fill Tank Z
= 19 x 17 x 16
= 5168 cm<sup>3

1</sup>₅ of volume of water in Tank Y at first = 5168 cm^3  
5₅ of volume of water in Tank Y at first = 5 x 5168 = 25840 cm³

Volume of water in Tank Y at first = 25840 cm³

Volume of water in Tank Z at first
= 19 x 17 x 19
= 6137 cm³

Total volume of water in Tank Y and Tank Z 
= 25840 + 6137
= 31977 cm³

Final volume of water in Tank Y after 11001 cm³ of water overflowed
= 31977 - 11001
= 20976 cm³

Base area of Tank Y
= 24 x 19
= 456 cm²

Height of Tank Y
= 20976 ÷ 456 
= 46 cm

Answer(s): (a) 25840 cm² ; (b) 46 cm