In a class of 30 girls, 13 are dancers and 23 are gymnasts. If 7 girls do both dance and gymnastics, what is the probability that a girl chosen at random does neither dance nor gymnsatics.

Answer: 1/30
Thanks to anyone who helps

1 answer

Only Dance = 13- 7 = 6
Only Gym = 23-7 = 16
both = 7
sum = 6 + 16 + 7 = 29
30 - 29 = 1
One does neither