Members in the club = No. of females + No. of males Concept No. of A : No. of B= Ratio of A:B ⇒ No. of females: No. of males =3:2 No. of females =15 ⇒15 : No. of males =3:2 Express the : as fractions ⇒15∕No. of males =3∕2 Cross multiply (The numerator from one side multiplies the denominator from the other side of the equation) No. of males ×3=15×2 Make No. of males the subject by dividing both sides of the equation by 3 No. of males =15×2∕3 3 goes into 15, 5 times ⇒ No. of males =5×2=10 Members in the club = No. of females + No. of males ⇒ Members in the club =15+10=25