M varies directly as n and inversely as the square of p. If M = 3, when n = 2 and p = 1, find M in terms of n and p.
-
A.
M = 2n/3p -
B.
M = 3n2/2p2 -
C.
M = n2/2p -
D.
M = 3n/2p2 -
E.
M = 2n/3p2
Correct Answer: Option D
Explanation
(M propto frac{n}{p^2})
(M = frac{kn}{p^2})
(3 = frac{k(2)}{1^2})
(3 = 2k implies k = frac{3}{2})
(M = frac{3n}{2p^2})