Question

The sum of first q term of ap is 63q-3q. If its p term is -60 .find the value of p

Answer 1

given that sq=63q-3q. when q =1 s1=63-3=60 s1=a1 when q=2 s2 =63(2)-3(2)=126-6=120, a2=s2-s1=60, so a1=60 and common difference is 60. ap=-60 ,a+(p-1)d=-60, 60+(p-1)d=-60 so, 60p-60=0, 60p=60,p=1. hope it helps you.