Question

in an ap of first term is 2 the sum of the first five terms is one fourth of the sum of next 5 terms find the sum of first 20 terms​

Answer 1

a=2

Sn=n/2{2a +(n-1) d}

It is given,

S5=1/4{S10-S5}

5/2{2*2+(n-1)d}. =1/4

Answer 2

hope it will help you ....