Question

if 30th term of Ap 7,13,19 is​

Answer 1

a= 7 , d= 13-7 = 6 , n= 30

An = a+(n-1)d = 7+ (30-1)6 = 7+29×6= 174+7= 181

Sn = n/2{2a+(n-1)d} = 30/2{14+29×6}

= 15×188= 2820