Question

If the shadow of a tree is 14 m long and the shadow of a person who is 1.8 m tall is 4 m long, how tall is the tree?

Which of the following proportions could not be used to solve the problem?

a: 14/1.8=x/4
b: x/14=1.8/4
c: x/1.8=14/4

Answer 1

Answer: $\frac{x}{14}=\frac{1.8}{4}$

Step-by-step explanation:

Let 'x' be the height of tree.

The length of shadow of a tree = 14 m

The length of shadow of a person =4 m

The height of person = 1.8 m

Since both man and tree are standing vertical to the ground.

Assume the formation of shadow is happening at the same time then the angle that the sun hits the earth making shadows of both person and tree will be equal.

By direct proportion , we have

$\frac{\text{height of tree}}{\text{length of shadow of tree }}=\frac{\text{height of person}}{\text{length of shadow of person}}\\\\\Rightarrow\frac{x}{14}=\frac{1.8}{4}$

Answer 2

The correct answer would be:

14/1.8 = x/4

I just finished with that assignment and it said it was correct :-)