I don't even have an idea of how to work out this question:
An initial investment of £1000 is places into a savings account that offers 2.2% interest every 3 months. The amount of money in the account £P, at the end of t years is fiven by
P = 1000 X 1.022 ^(4t) ....( and that's a mutiply sign btw)
Find, to the nearest year, how long it will take for the investment to double in value. (4 marks)