How many numbers between 11 and 90 are divisible by 7?

The correct answer is Option (1) → 11

The numbers divisible by 7 form an arithmetic progression with common difference 7, so their count is (last − first) ÷ 7 + 1.

• First multiple of 7 after 11: 14

• Last multiple of 7 before 90: 84

• Count \(=\displaystyle\frac{84-14}{7}+1=10+1=11\)