Malacolm buys a caravan for £12000. it depreciates by 31% per year. how much is it in 7 years?

12000x0.69 to the power of 7
Hope this helps

This is exponential decay of the form:

F=Ir^t, F=final amount, I=initial amount, r=rate, t=time, in this case:

F=12000(1-31/100)^t

F=12000(0.69)^t  so after 7 years...

F=12000(0.69)^7

F=£893.56