Question

how many numbers between 400 to 700 are divisible by either 9 or 11

Answer 1

11×9=99
the biggest number by divisible by 99 in 400 to 700 is 693.
hence , tn = 693
and
tn = a + (n-1)d
693=495+(n-1)99
198=(n-1)99
2+1=n
n=3
hence ,the total number is 3 when divided by 11 or 9 in 400 to 700..

Answer 2

Thank you for asking this question:

We will assume as the least no divisible by 9 is 405

And the most is 693

So AP will be formed

405,414,423..........................693

The formula for nth term is given by:

an=a+(n-1)d

So, 693=405+(n-1)9

288=(n-1)9

32=n-1

So, n=33

If there is any confusion please leave a comment below.