An object 3.6ft tall casts a shadow........

Question

An object 3.6ft tall casts a shadow that is 10.8ft long. How long in feet would the shadow be for an object which is 19.5 feet tall? 

A)12.3ft

B)6.5ft

C)26.7ft

D)58.5ft

Answer 1

Qx = y where Q is our constant.

To find out constant, we put in what information we do know.

3.6ft * Q = 10.8ft

 

We divide both sides by 3.6ft to isolate our constant, and we get

Q = 3

 

So now our x is 19.5ft

 

19.5ft * 3 = 58.5ft

Answer 2

let x be the shadow cast by object 19.5 ft tall

 

 

10.8/3.6 = x/19.5

 

(19.5)(10.8/3.6) = x = 58.5 ft. long

 

Answer 3

Set up a proportion:

 

10.8 ft            x ft

----------  =  ----------

 3.6 ft           19.5 ft

 

Cross multiply:

 

(10.8)(19.5) = (3.6)x

 

Solve for x.