Question

find the sum of first 10 terms of the A.P . 4+6+8........

Ans = 130

Answer 1

a=4
n=10
d=6-4=2
formula= Tn=n/2[a+(n-1)d]
=> 10/2[4+(10-1)2]
=> 5[4+9×2]
=>5[13×2]
=>5×26
=> 130