A biology class has a total of 45 students. The number females is 9 less than the number of males. How many males and how many females are in class?

There are 27 males & 18 females in the class

Step-by-step explanation:

Suppose,

m=number of males

f = number of females

Given that,

The number females is 9 less than the number of males

∴ f = m-9 ... (1)

and total students = 45

∴ m+f = 45

⇒ m + (m-9) = 45 [From (1) ]

Add like terms

2m-9=45

Add 9 to both sides

2m=45+9

⇒2m = 54

Divide both sides by 2

m = 54/2

∴m=27

∴There are 27 males in the class.

now,

f = m-9 [From (1) ]

⇒f = 27-9 [∵m=27]

∴m = 18

∴There are 18 females in the class