Question

When a 40-foot pole casts a shadow of

30 feet, how tall is a nearby tree that
casts a shadow of 15 feet?

Answer 1

20

Explanation:

It tells you that a 40 foot pole casts a 30 foot then it asks you how tall is a tree if it casts a 15 foot shadow. We see that 30 is exactly 2 times 15

30 = 2 * 15

So we simply do that to 40 too.

40 / 2 = 20

So 20 is our answer.

Answer 2

Set up a ratio with height over shadow height:

40/30 = x/15

Cross multiply:

40 x 15 = 30x

600 = 30x

Divide both sides by 30:

X = 20

The tree is 20 feet tall.