Answer
a. $0.301$
b. $0.592$
c. $0.412$
Work Step by Step
Total number is 15747
a. Male and 19 years or under
P(Male and 19 years or under)=$4746/15747=0.301$
b. Age 20 or female (add up numbers for age 20, and female separately, 3178 and 7697)
P(Age 20)=$3178/15747=0.202$, P(female)=$7697/15747=0.489$
P(Age 20 and female)=$1553/15747=0.099$
P(Age 20 or female)=$0.202+0.489-0.099=0.592$
c. At least 20 years old (add up all number 20+ years old 6484)
P(At least 20 years old)=$6484/15747=0.412$