jmc

Question

Danny Henry made a waffle on his six-inch-diameter circular griddle using batter containing a half a cup of flour. Using the same batter, and knowing that all waffles have the same thickness, how many cups of flour would Paul Bunyan need for his 24-foot-diameter circular griddle?

Accepted Answer

Say Paul and Danny's griddles have diameters d_1 and d_2, respectively. Paul's griddle has d_1d_2=24 ft.5 ft=48 times the diameter and therefore d_1^2/4 d_2^2/4=(r_1r_2)^2=48^2=2304 times the area. It requires 2304 times as much flour, or 23040.5=1152 cups of flour.