(a) Solve, correct to two decimal places, the equation \(4x^{2} = 11x + 21\).

(b) A man invests £1500 for two years at compound interest. After one year, his money amounts to £1560. Find the :

(i) rate of interest ; (ii) interest for the second year.

(c) A car costs N300,000.00. It depreciates by 25% in the first year and 20% in the second year. Find its value after 2 years.