Question

In an AP the sum of the first 3 terms is -36 & the sum of the last 3 is 27 if there are 10 terms what are the 1st term & the common difference respectively

Answer 1

SOLUTION:

Let first three terms be: a, a+d, a+2d

a+2d+a+a+d=-36

3a+3d= -36

a+d= -12..................1

Last Three Terms will be: a+7d, a+8d, a+9d

SUM:

3a+24d=27

a+8d = 9..............................2

FROM 1. and 2.

d=3, a=-15