Question

Sum of first hundred numbers common to the two A.P.’s 12, 15, 18, … and 17, 21, 25 …..is

Answer 1

Answer:

61500

Step-by-step explanation:

a=21

d=1

Sn=n/2(A2+(n-1)d)

=100/2(2×21+(100-1)12)

=50(42+99×12)

=61500