Question

If the number of numbers between 100 and 1000 that are divisible by 11 is x,

Answer 1

here, t1=121 d=11, tn=990.

we know that,

tn=a+(n-1)d

990=121+(n-1)11

990=121+11n-11

990=110+11n

990-110=11n

880=11n

880/11=n

80=n. : there are 80 number are divisible by 11 in 100to1000.