If you are rounding to the nearest ten it would be 30. If you're rounding the the nearest whole number you don't change the 25 at all. If you are rounding the the nearest 20 it would be 20. If you're rounding to an even number you could round up or down to get 26 or 24. Normally you would round up in that situation so you would use 26. I think in this specific situation they want it rounded to the nearest ten. In that case it would be 30.
