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

1. How much water was there in Tank J at first?
2. Cole then poured all the water from Tank K into Tank J. 8496 cm³ of water overflowed from Tank J. What was the height of Tank J?

(a)
Volume of water to fill Tank K
= 18 x 14 x 14
= 3528 cm<sup>3

1</sup>₅ of volume of water in Tank J at first = 3528 cm^3  
5₅ of volume of water in Tank J at first = 5 x 3528 = 17640 cm³

Volume of water in Tank J at first = 17640 cm³

Volume of water in Tank K at first
= 18 x 14 x 18
= 4536 cm³

Total volume of water in Tank J and Tank K 
= 17640 + 4536
= 22176 cm³

Final volume of water in Tank J after 8496 cm³ of water overflowed
= 22176 - 8496
= 13680 cm³

Base area of Tank J
= 20 x 18
= 360 cm²

Height of Tank J
= 13680 ÷ 360 
= 38 cm

Answer(s): (a) 17640 cm² ; (b) 38 cm