If 1/5 of a given number is 20, what is one/four of the given number

25

Step-by-step explanation:

1/5 equals 20/1 so then you'd write out the problem like this: 1/4=?/1

as you can see in the first part, 5 times 20 is 100 and the ones cancel out. If you cancel out the ones in the second part, you're left with 4 times what equals what, and the answer is 25.