The shadow of a tree on the ground is 17 feet. If the shadow of a 5 1/2 feet tall person standing up straight is 11 feet, how tall is the tree? I know the answer is 8 1/2 ft. but how do you solve it?

Question

zpupster · Answer

it is a ratio  11 is to 5 1/2 as 17 is to ???

anonymous · Answer

8 1/2

zpupster · Answer

yes that is right, but how did you solve it

anonymous · Answer

that's what I don't know how to do, can you help me please

zpupster · Answer

sure

anonymous · Answer

thanks

zpupster · Answer

I set them like this:

11/( 1/2)  =  17/x and then solve for x like so

11 x = 17(5 1/2)

x = 17(5 1/2)/11

do the math and you should come out with your answer

I cross mult and then divided to isolate x

anonymous · Answer

oh that makes sense thank you! :)

zpupster · Answer

good job!!

anonymous · Answer

thanks you now I get it :D