This is the question:

The first term of an arithmetic series is 9 and the seventh term is three times the second term.

a) find the sum of the first 32 terms

b) how many more terms must be added for the sum of the A.P. to be 5040?

I have managed to work out d=6 and i think a) is 3264 but i have no idea what b) means PLEASE help !!!