if 15 is equal to 25% of a value, and we want to know what the value is all we have to do(and you can use this trick whenever it is a question like this):
Every 25% is 15 so, 25%:15. 50% would be 30 because 2 * 25% is 50% and 2 * 15 is 30. Then you do 2 times both sides like before, 2 * 50% is 100% and 2 * 30 is 60. So, 60 is the value because it is 100%!
I hope this helped! Have a splendid day!
