Question

The given expression (11n + 10) is for numbers in a series (taking n = 1, 2, 3, 4…… in order).

Which of the following number belong to the given series.

• A. 12
• B. 100
• C. 1000
• D. 10000

Answer 1

The correct option is C

1000

For the given series 11n + 10

If we take n = 1, 2, 3, 4……. In order

We get the numbers 21, 32, 43, 54, 65, 76, 87, 98, 109…..

All these numbers leaves a remainder 10 when divided by 11.

When we divide 1000 by 11 , the remainder is 10.

Also, 11 x 90 + 10 = 1000 (taking n= 90)

$\therefore$1000 belongs to the series.