Question

The value of y varies jointly with the values of x and z. When x=4 and z=9, the value of y is 360. What is the value of y when x=5 and z=12?

Answer 1

y = k * z , where k is any constant
x=4, z=9 , y=360

360 = k (4)(9)
360 = 36 k
k = 360/36
k = 10

y = 10 * z

when x=5 and z = 12
y = 10 (5)(12)
y = 600