A shop sells bicycles and tricycles. In total there are 7 cycles (cycles include both bicycles and tricycles) and 19 wheels. Determine how many of each there are, if a bicycle has two wheels and a tricycle has three wheels. Choose the correct choice:
A) b=2,t=3
B) b=5,t=3
C) b=6,t=2
D) b=2,t=5
E) b=3,t=4
Let b be the number of bicycles and let t be the number of tricycles.   Set up the equations   b+t=7............(1)   2b+3t=19............(2)   Rearrange equation (1) and substitute into equation (2)   t=7-b   2b+21-3b=19   -b=-2   b=2   Calculate the number of tricycles t   t=7−b   =7−2   =5   There are 5 tricycles and 2 bicycles.   Answer is b=2,t=5.
<result>D</result>
A shop sells bicycles and tricycles. In total there are 7 cycles (cycles include both bicycles and tricycles) and 19 wheels. Determine how many of each there are, if a bicycle has two wheels and a tricycle has three wheels.