A and B are two towers.the height of A is 20% less than the height of B.how much per cent is B's height more than that of A

Let's break this down:

1. Let's assume the height of tower B is 100 units (this number is chosen for simplicity and does not affect the final percentage result).

2. According to the problem, tower A is 20% less tall than tower B. So, A's height is 100 - 20% of 100 = 100 - 20 = 80 units.

3. Now, we need to find out how much taller tower B is compared to tower A. The difference in height is 100 - 80 = 20 units.

4. To express this difference as a percentage of A's height, we divide the difference by A's height and multiply by 100. So, (20/80) * 100 = 25%.

So, tower B is 25% taller than tower A.