60/( 1+20%)=50
2。 There are 60 footballs in the school, which is 20% less than volleyball. How many volleyballs are there in the school?
60/( 1-20%)=75
3。 There are 60 footballs in the school, and the number of volleyball is 20% more than football. How many volleyballs are there in the school?
60*( 1+20%)=72
4。 There are 60 footballs in the school, and the number of volleyball is 20% less than football. How many volleyballs are there in the school?
60*( 1-20%)=48