Question

Find the sum of all 3 digit number which are divisible by 11

Answer 1

Answer:

111 is the answer of this question

Answer 2

Answer:

nth term =an =990

a= 110

an = a + (n -1)d

990= 110 + (n-1) 11

880/11 = n-1

81= n

Sn =n/2 { 2a + (n-1)d}

S81= 81/2 {2×110 + (81-1)11}

= 81/2 {220 +880}

=81/2 { 1100}

=81×550

=44550