How many numbers from 1 to 100 are there each of which is not only exactly divisible by 4 but also has 4 as a digit?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 7
A number must pass both tests: it is a multiple of 4, and one of its digits is 4. Listing the numbers with a 4 is quicker than listing the 25 multiples of 4.
Numbers ending in 4: 4, 14, 24, 34, 44, 54, 64, 74, 84, 94; of these, 4, 24, 44, 64, 84 are multiples of 4
Numbers from 40 to 49: of these, 40, 44, 48 are multiples of 4 (44 is already counted)
Total: \(5+2=7\) numbers: 4, 24, 40, 44, 48, 64, 84