What is 25 of what number is 20?

The equation "25 of what number is 20" can be written as:

25x = 20

To solve for x, we need to isolate it on one side of the equation. We can do this by dividing both sides by 25:

25x/25 = 20/25

Simplifying:

x = 0.8

So the number we are looking for is 0.8.

Alternatively, we can also solve this problem using proportions. We know that "25 of x" is equal to 20, so we can write:

25/x = 20/1

Cross-multiplying:

25 = 20x

Dividing both sides by 20:

x = 25/20 = 1.25

So the number we are looking for is 1.25, which is the same as 0.8 when rounded to one decimal place.