Algebra word problem

Question

A signpost 4 feet tall casts a shadow 1 1/2 feet long. A. The same time of day a nearby print shop cast a shadow 18 3/4 feet long how tall is the shop?

Answer 1

Mike, this is a ratio problem.  If I say that a 6-ft building casts an 8-ft shadow, then a 12-ft building should cast a 16-ft shadow, because 6/8 = 12/16.  You can cross multiply. 6 x 16 = 12 x 8.  Can you figure it from here?

Answer 2

Let h = the height of the shop.  Use a proportion to find h:

 

 4 feet           h feet

-----------  =  -------------

1.5 feet       18.75 feet

 

Multiply both sides by 18.75:

 

4*(18.75)

-------------  =  h

     1.5

 

Can you finish it from here?