Question

A collector has 120 movies posters and 100 band posters. She wants to sell movie posters but still have her poster collection maintain the same ratio of 120: 100. If she sells 24 movie posters, how many band poster should she sell? explain

Answer 1

120:100 or 6:5 so 24:x
if ratios are the same then the reciprocal of one of the ratios times the other ratio should equal 1 so 6/5 times x/24=1
6x/120, x=20