How many paying stones, each measuring 2 1/2 m * 2 m are required to pave a rectangular court yard 20 m long and 16 1/2 m board?  Choose the correct choice.
A) 66
B) 18
C) 16
D) 10
E) 15
20 * 33/2 = 5/2 * 2 * x =&gt; x   = 66   66nswer:66
<result>A</result>
How many paying stones, each measuring 2 1/2 m * 2 m are required to pave a rectangular court yard 20 m long and 16 1/2 m board?