Mathematics 2008 JAMB Past Questions - Question 16: If p varies inversely as the square of q and p=8 when q=4,find q when p=32

Correct Answer

D

Explanation

P = K/q² , i.e q² = 128/32, i.e x = ±2If p varies inversely as the square of q, we can express this relationship as:p = k / q^2where k is the constant of variation.Given that p = 8 when q = 4, we can substitute these values into the equation to solve for k:8 = k / 4^28 = k / 16k = 8 * 16k = 128Now that we have the value of k, we can use it to find q when p = 32:32 = 128 / q^2To solve for q, we can rearrange the equation:q^2 = 128 / 32q^2 = 4q = √4q = ±2Therefore, when p = 32, q can be either 2 or -2.