Question

At a certain time of day, a person 6 ft tall casts a 4 ft shadow. How long is the shadow cast by a 21 ft tree at the same time? A. 12 ft B. 14 ft C. 19 ft D. 15 Ft

Answer 1

we have

6 ft of a person ----> 4 ft shadow

21 ft of a tree -------> x

$\begin{gathered} \frac{6}{21}=\frac{4}{x} \\ 6\times x=21\times4 \\ 6x=84 \\ \frac{6x}{6}=\frac{84}{6} \\ x=14 \end{gathered}$

answer: B. 14 ft