Of the 15-year-olds at a karate school, 6 have black belts and 20 have brown belts. among the 16-year-olds, 5 have black belts and 9 have brown belts. which age group has a higher ratio of black belts to brown belts?

M? aoc=96 ? space, m, angle, a, o, c, equals, 96, degree \qquad m \angle boc = 8x - 67^\circm? boc=8x? 67 ? space, m, angle, b, o, c, equals, 8, x, minus, 67, degree \qquad m \angle aob = 9x - 75^\circm? aob=9x? 75 ? space, m, angle, a, o, b, equals, 9, x, minus, 75, degree find m\angle bocm? bocm, angle, b, o, c: