Solve the inequality: -7 \(\leq\) 9 - 8x < 16 - x

The nth term of a sequence is given by 2\(^{2n - 1}\). Find the sum of the first four terms.

Integrate \(\int_{-1} ^{2} (2x^2 + x) \mathrm {d} x\)

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.