Let the total number of women be 100 (for simplicity).
Women above 30 years of age:40% of the women are above 30 years of age, which means:
Women above 30 years = 40% of 100 = 40 women
Women less than or equal to 50 years of age:80% of the women are less than or equal to 50 years of age, which means:
Women less than or equal to 50 years = 80% of 100 = 80 women
Women above 50 years of age:Since 80% are less than or equal to 50 years, the remaining 20% are above 50 years of age, which means:
Women above 50 years = 20% of 100 = 20 women
Women who play basketball:20% of all women play basketball, which means:Total basketball players = 20% of 100 = 20 women
Women above 50 years of age who play basketball:30% of the women above 50 years play basketball, which means:
Basketball players above 50 years = 30% of 20 = 6 women
Women less than or equal to 50 years who play basketball:
The total number of basketball players is 20, and 6 of them are above 50 years of age.
Therefore, the number of players less than or equal to 50 years of age is:Basketball players less than or equal to 50 years = 20 − 6 = 14 women
Percentage of players who are less than or equal to 50 years of age:Percentage of players less than or equal to 50 years =

Thus, 70% of the basketball players are less than or equal to 50 years of age.