Question

A tree is 15 feet tall and casts a shadow of 9 feet. How long is the shadow of a tree 25 feet tall?

Answer 1

The shadow is 15 feet long.

Explanation:

This is a proportion question. Build a proportion using two fractions.

`\frac{\text{tree height}}{\text{shadow length}}`

`(15)/(9)=(25)/(x)`

"Cross-multiply" -- you might know this as the Means-Extremes Property of Proportions.

`15x=(25)(9)\\15x=225\\x=15`

Answer 2

I’m not sure if this is right but I would try to think of the question as a ratio. 15ft casts a 9ft shadow (15:9). But u want to find out the length of the shadow when the tree is 25ft. The initial ratio can be divided by 3 (5:3) this makes it easier to get the 25ft tree and it’s shadow equivalent. 25/5=5 so a 25ft would cast a 15ft shadow

Answer:15ft shadow