. How many numbers of two digits are divisible by 7
14 is the first two digit number and 98 is the last two digit number divisible by 7,
This will give us an A.P series as,
Where the first term is 14, common difference is 7 and the last term is 98,
Let us assume that the A.P series goes till ,nth term
So, nth term =98
Putting these value in the formula, we will get,
14 + (n -1)× 7 =98,
⇒14 +7n -7 =98
Hence there are 13 numbers divisible by 7.
There are 13 two digit numbers divisible by 7.