num of females + num of males = 100
num of females + 3(num of females) = 100
4(num of females) = 100
num of females = 25
num of ppl who chose ping-pong = 20
num of females who chose ping pong = 60% of 20 = 12
num of females who didn't choose ping-pong = 25 - 12 = 13
probability that a person is female = num of females / num of ppl
probability that a person is female = 25 / 100
probability that a person is female = 0.25
probability that a person chose ping-pong = num of ppl who chose ping-pong / num of ppl
probability that a person chose ping-pong = 20 / 100
probability that a person chose ping-pong = 0.2
probability that a person is a female and chose ping pong = \(\frac{\text{num of females who chose ping-pong}}{\text{num of females}}\)
probability that a person is a female and chose ping pong = 12 / 100
probability that a person is a female and chose ping pong = 0.12
probability that a person is female or chose ping-pong = (20 + 13) / 100
probability that a person is female or chose ping pong = 33 / 100
probability that a person is female or chose ping pong = 0.33
