No, 75/100 is equal to 3/4 and an example of anything equal to 1 is a number over itself. For example: 1/1 = 1 23/23 = 1 100/100 =1 75/75 = 1 yeah you probably get the point now
90/2 is 45.. 60/2 is 30.. 30+45=75... 75 students would be able to be in each of the 2 groups, each containing 45 girls and 30 boys ... Hope I helped (: