Question

Thomas happened to notice that at 4:00 p.m. on his uncle's farm, a fence post that was 5 feet tall cast a 3 foot shadow. he also noticed that a nearby tree cast a 12 foot shadow. how tall is the tree?

Answer 1

If he noticed both of them at exactly 4pm, the fence post would be 5:3, 12 is 4 x 3, giving you the multiplier, so 5 x 4 is 20, a 20:12 ratio which means that the tree should be approximately 20 feet tall.

Answer 2

I used the proportion:
5:3=x:12
x=((12)(5))/3=20
20 feet