There is a total of 63 bikes if the ratio of blue to black bikes is 4 to 5 how many are blue

Since the given ratio is blue:black is 4:5

4+5=9

4/9 = 0.44 ~ 44%

5/9 = 0.56 ~ 56%

Since there are a total of 63 bikes and 44% of these bikes are blue we just multiply 44% with the total number of bikes.

Solution:

1. 0.44 x 63 = 28

2. 0.56 x 63 = 35

Conclusively, there are 28 bikes that are colored blue.