P varies jointly as m and u and varies inversel... - JAMB Mathematics 2013 Question

P \(\propto\) mu, p \(\propto \frac{1}{q}\)

p = muk ................ (1)

p = \(\frac{1}{q}k\).... (2)

Combining (1) and (2), we get

P = \(\frac{mu}{q}k\)

4 = \(\frac{m \times u}{1}k\)

giving k = \(\frac{4}{6} = \frac{2}{3}\)

So, P = \(\frac{mu}{q} \times \frac{2}{3} = \frac{2mu}{3q}\)

Hence, P = \(\frac{2 \times 6 \times 4}{3 \times \frac{8}{5}}\)

P = \(\frac{2 \times 6 \times 4 \times 5}{3 \times 8}\)

p = 10