To simplify ratios find the greatest common multiple between the two numbers. For 32 they are 1,2,4,8,16,32 and for 48 they are 1,2,3,4,6,8,12,16,24,48. They both share 1,2,4,8 and 16 and the greatest is 16. Now divide both numbers by 16 to get the new ratio which is 2:3
