The price of all rail season tickets to London increased by 4%. a) The price of a rail season ticket from Cambridge to London increased by £121.60. Work out the price before this increase.

b) After the increase, the price of a rail season ticket from Brighton to London was
£2,828.80. Work out the price before this increase.

c) If the price of rail season tickets increases by 4% every year, work out the price after 3 years of a season ticket that currently costs £3048. You must use the compound interest formula in your workings.