<PRE><B>Question 836973</B>

Set:

# of Bicycles = B

# of wheels needed per bike = 2B


# of Tricycles = T

# of wheels needed per trike = 3T

T = 1/2B
B = 2T

2B + 3T = 21 total wheels

Plugging in B = 2T:

2(2T) + 3T = 21

4T + 3T = 21

7T = 21

T = 3
B = 6

6 Bicycles and 3 Tricycles

CHECK:

6(2 wheels per bike) + 3(3 wheels per trike) = 12 + 9 = 21 Wheels total


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