Question

find the sum of 1 to 100 natura numbers which are divisible by 3​

Answer 1

Answer:

a=3 d=3 an=99

Step-by-step explanation:

an=a+(n-1)d

99=3+(n-1)3

99-3=3n-3

3n=99-3+3

n=99/3

n=33

S33=n/2(2a+32d)

S33=33/2(2×3+32×3)

S33=33/2(6+96)

=33/2×102

=33×51

=1683