9 out of 10 cheerleaders are 64" tall.  The 10th cheerleader is 60" tall.  If they build a human pyramid, where 4 girls are on the bottom,  3 stand on top of the 4, 2 stand on top of the 3 and the shortest girl is at the top, how tall is the human pyramid in feet?
All but one cheerleader is 64" tall and these cheerleaders make up the bottom 3 layers of the pyramid. So, when standing on top of each other, they are 64*3 = 
<gadget id="calculator">64*3</gadget>
<output>192</output>
192" tall.
The shortest cheerleader is at the top of the pyramid and is 60" tall so the pyramid is 192+60 = 
<gadget id="calculator">252</gadget>
<output>252</output>
252" tall
12" are in 1 foot and the pyramid is 252" tall so it's 252/12 = 
<gadget id="calculator">252/12</gadget>
<output>21</output>
21 feet tall.

<result>21</result>