Question

Find the sum of the number in between 1 and 1000 which are divisible by 9 options a) 55944 b) 54954 c) 99994 d) 99894

Answer 1

Answer:

a) 55944

Step-by-step explanation:

The series is

9,18,27,36...999

so first we have to find how many terms

an=a+(n-1)d

999=9+(n-1)9

999=9n

n=111

Sn=n/2×(2a+(n-1)d)

where

n=no.of terms

a=first term

d=common difference

=111/2[2×9+(111-1)×9]

=111/2[18+990]

=111×1008/2

=111×504

=55944