A Rule for Estimating the Number of Board Feet of Lumber

Multiple Choice

A rule for estimating the number of board feet of lumber that can be cut from a log depends on the diameter of the log. To find the diameter, \mathrm{d} , required to get 7 board feet of lumber, we use the equation $\left( \frac { d - 4 } { 4 } \right) ^ { 2 }$ =49 . Solve this equation for d. Are both answers reasonable?

A) 32,-24 ; No, only 32 feet is a reasonable answer.
B) 11,-28 ; No, only 11 feet is a reasonable answer.
C) 24,-32 ; No, only 24 feet is a reasonable answer.
D) 28,-28 ; No, only 28 feet is a reasonable answer.