If P varies inversely as the square root of q, where p = 3 and q = 16, find the value of q when p = 4.

Tade bought 200 mangoes at 4 for ₦2.50. 30 out of the mangoes got spoilt and the remaining were sold at 2 for ₦2.40. Find the percentage profit or loss.

The simple interest on ₦8550 for 3 years at x% per annum is ₦4890. Calculate the value of x to the nearest whole number.

Simplify 81\(^{\frac{-3}{4}}\) x 25\(^{\frac{1}{2}}\) x 243\(^{\frac{2}{5}}\)

Find the value of \(\frac{(0.5436)^3}{0.017 \times 0.219}\) to 3 significant figures.