Question

plz ans this step by step

Answer 1

TO FIND THE SUM OF INTEGERS BW 100 AND 200

i)Divisible by 3

A.P->102,105,108,111-------------------198
a=102 d=105-102 an=198 n=?
=3

an=a+(n-1)d
198=102+(n-1)3
198-102=(n-1)3
96=(n-1)3
96/3=(n-1)
32=(n-1)
32+1=n
n=33

Sn=n/2{2a+(n-1)d}
=33/2{2×102+(33-1)3}
=33/2{204+32×3}
=33/2{204+96}
=33/2{300}
2 divides 300 and makes it 150
=33×150
=4950 ans..