Question

P varies directly as q and inversely as y. One set of values is P = 0.064, q = 16 and y = 5. Find P when q = 12 and y = 10.

Answer 1

y varies inversely as x means y=kx
y varies directly as x means y=k/x

p varies directly as q and inversely as y
p=(qk)/y

0.064=(16k)/5
find k
times both sides by 5
0.32=16k
divide both sides by 16
0.02=k

p=(0.02q)/y

q=12
y=10
p=(0.02*12)/10
p=(0.24)/10
p=0.024