Of the 15 year olds at karate school 8 have black belts in 20 had Brown belts among 16 year olds 10 have black belts in 17 have Brown belts. which age group has a higher ratio of black belts to Brown belts

16 year olds had the higher ratio of black belts to brown belts.

Step-by-step explanation:

15 year olds: 8/28 students had black belts

8/28 = 28.6% had black belts

16 year olds: 10/27 students had bald belts

10/27 = 37.0% had black belts