Find k and y when x = 6 and z = 8, if y varies jointly as x and z and y = 60 when z = 3 and x = 4.
a)k = 1/5 , y = 240 b)k = 5 , y = 240 c)k = 1/5 , y = 9.6 d)k = 5 , y = 9.6
y = k x z
60 = k * 3 * 4
k = 5
y = 5* x * z
= 5 * 6 * 8 = 240
