Bala sold an article for #6,900.00 and made a profit of 15%. Calculate his percentage profit if he had sold it for N6,600.00. 

If 3p = 4q and 9p = 8q - 12, find the value of pq.

If (0.25)\(^y\) = 32, find the value of y.

There are 8 boys and 4 girls in a lift. What is the probability that the first person who steps out of the lift will be a boy? 

Simplify: \(\frac{x^2 - 5x - 14}{x^2 - 9x + 14}\)