Question

y varies jointly with p and q. When p = 5 and q = 2, y = 80. Find y when p = 4 and q = 5.

Answer 1

y=kpq
80=k*5*2=10k
k=8

Answer 2

y=8pq
y=8*4*5=8*20=160

Answer 3

thank u :)