Question

There were 3 similar metal balls in the tank.if the 3 metal balls were out,the water in the tank would drop from 15 cm to 6 cm.find the volume of each metal ball.

Answer 1

let the base area of the tank be x cm^2

volume including balls = 15x
volume without the balls = 6x
volume of the 3 balls = 9x
volume of each ball = 3x

Unless we know the base dimension of the tank, that is as far as you can go.

e.g.
if the tank has a base of 40 by 50 and a height of 30 cm
volume with the balls = 40(50)(15) =30,000
volume without the balls = 40(50)(6)= 12,000
So the volume of the 3 balls = 18,000
and the volume of each ball is 6,000

(notice that in this case, x = 2000
and each ball is 3x = 6000)