In a wholesaler, ⁵₇ of the customers were female. There were 63 more female customers. Within five minutes, some female customers left the wholesaler. As a result, there were ³₇ as many male customers as female customers. How many female customers left the wholesaler during the five minutes?
Number of female customers = 5 u
Total number of customers = 7 u

Number of male customers
= 7 u - 5 u
= 2 u

5 u - 2 u = 63
3 u = 63

1 u = 63 ÷ 3 = 21

Number of female customers at first
= 5 u
= 5 x 21
= 105

Number of male customers
= 2 u
= 2 x 21
= 42

The number of male customers remains unchanged.
3 p = 42

1 p = 42 ÷ 3 = 14

New number of female customers
= 7 p
= 7 x 14
= 98

Number of female customers who left
= 105 - 98
= 7

Answer(s): 7