Answer:
C (32)
Step-by-step explanation:
12 sneakers / 9 boots = x sneakers / 24 boots
the ratio is 4:3 so divide 24 by 3 and multiply by 4
12 / 9 = (24 / 3 x 4) / 24
12 / 9 = 32 / 24
32 students wore sneakers
they are 11 years old