Question

At a certain time a tree 6 m high caste a shadow of lenghth 8 m at the same time a pole casts a shadow of lenghth 20 meters find the height of the pole

Answer 1

it can be expressed in the proportion

6:8::x:20

we know the proportion rule to find out a term (product of extremes=product of means)

6*20=8*x

120=8x

x=120/8

x=15

the pole is 15 meters tall.