a pole cast a shadow that is 15 feet, a man standing next to the pole casts a shadow 5 feet , the man is 6 feet tall how tall is the pole

Question

how tall is the pole

Answer 1

For the man, the ratio of height/shadow = 6/5

 

For the pole, the ratio of height/shadow = x/15, where x is the unknown height.

 

6/5 = x/15

 

Solve for x.  The units are feet.

Answer 2

x=height of the pole

x/15=6/5

cross multiply or multiply both 6 and 5 by 3 to get 18 feet for the height of the pole

if you cross multiply...

5x=15*6

5x=90

x=18 feet

or,

a 6 foot man casts a 5 foot shadow

the pole casts a shadow 3 times as long (15 feet) so the pole must be 3 times as tall as the man