you want to make the fractions have an equal denominator so make 1/3 5/15s and 2/5 to 6/15's, 5+6= 11/15s that leaves 4/15's for the lower part of the school
4 divided by 15 is 4.6 repeating so divide 1200 by 4.66 and boom
If multiplying by 1/4 makes a positive number smaller then dividing by 1/4 makes the number its being dividing to see how many times 1/4 can be put into that number. For Example,
