# A.P & G.P ............

*label*Mathematics

*timer*Asked: May 2nd, 2015

**Question description**

The first, twelfth and last term of an

arithmetic progression are 4, 3112

, and 37612

respectively. Determine (a) the number of terms in

the series, (b) the sum of all the terms and (c) the

‘80’th term.