Answer :
no. of FEMALES =4/5(no. of members in club)
in that
no. of females over 20 years old=1/3(no. of FEMALES)=1/3(4/5(no. of members in club))
=4/15(no. of members in club)
no. of females over 20 years old/no. of members in club=4/15
in that
no. of females over 20 years old=1/3(no. of FEMALES)=1/3(4/5(no. of members in club))
=4/15(no. of members in club)
no. of females over 20 years old/no. of members in club=4/15