Answer: To be divisible by both 5 and 4, a number must be divisible by 20. The first two-digit multiple of 20 is 20 itself, and the last two-digit multiple of 20 is 100. Therefore, the possible two-digit numbers that are divisible by 5 and 4 are 20, 40, 60, 80, and 100. Out of these, only 20, 40, 60, and 80 are two-digit numbers. So there are four two-digit numbers that are divisible by 5 and 4.
Explanation: