Question

hii!!
how to find n=81
because counting in hand is a difficult task

Answer 1

The first natural number which is a multiple of 11 and has 3 digits is 110.

The last natural number which is multiple of 11 and has 3 digits is 990.

we can write 110=11x10

and 990=11x90.

It means there are 90-10 natural numbers and 1 natural number that is 110

so total =80+1=81

because 990=110 + (n-1)d.

990=110 + (n-1)x11

990-110=11n-11

880+11=11n

891=11n

n=891/11=81

Answer 2

hope this helps you ....