Class 4T and Class 4U have a total of 170 students. ¹₆ of the students in Class 4T and ⁶₁₁ of the students in Class 4U are boys. The number of girls in Class 4T is equal to the number of girls in Class 4U. Find the total number of girls in the 2 classes.
Fraction of Class 4T that are girls
= 1 - ¹₆ 
= ⁵₆

Fraction of Class 4U that are girls
= 1 - ⁶₁₁ 
= ⁵₁₁ 
 
The number of girls in Class 4T is equal to the number of girls in Class 4U.

The numerators are the same.  

⁵₆ Class 4T = ⁵₁₁ Class 4U 

Number of students in Class 4T = 6 u
Number of students in Class 4U = 11 u

Total number of students 
= 6 u + 11 u
= 17 u

17 u = 170

1 u = 170 ÷ 17 = 10

Number of girls in Class 4T =5 u
Number of girls in Class 4U =5 u

Total number of girls
= 5 u + 5 u
= 10 u
= 10 x 10
= 100

Answer(s): 100