Respuesta :

Answer:

28 blue bikes

Step-by-step explanation:

There follows a relatively simple method for solving this problem:

Let c be a counter.  Then 4c + 5c = 63, and 9c = 63.  Thus, c = 7.

Then the number of blue bikes is 4(7) = 28, and the number of black ones is 5(7) = 35.  Note that 28 + 35 comes to 63.

There are 28 blue bikes.

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