In a supermarket, ⁵₈ of the customers were female. There were 84 more female customers. Within five minutes, some female customers left the supermarket. As a result, there were ⁷₁₀ as many male customers as female customers. How many female customers left the supermarket during the five minutes?
Number of female customers = 5 u
Total number of customers = 8 u

Number of male customers
= 8 u - 5 u
= 3 u

5 u - 3 u = 84
2 u = 84

1 u = 84 ÷ 2 = 42

Number of female customers at first
= 5 u
= 5 x 42
= 210

Number of male customers
= 3 u
= 3 x 42
= 126

The number of male customers remains unchanged.
7 p = 126

1 p = 126 ÷ 7 = 18

New number of female customers
= 10 p
= 10 x 18
= 180

Number of female customers who left
= 210 - 180
= 30

Answer(s): 30