algebra word problem

Question

If a 20-meter flagpole casts a shadow that is 50 meters long, how long is the shadow cast by a tree that is 36 meters high?

Answer 1

Height flagpole / flagpole shadow length =

Height tree / tree shadow length

20 m / 50 m = 36 m / x

Simplify:

2/5 = 36 m / x

Mulitply by x and divide by 2/5:

x = 36 m × 5/2 = 90 meters = length of tree shadow

Check: 36/90 = 2*18/(18*5) = 2/5

Answer 2

36 x 50/20 = 36(2.5) = 90 meters long

90/36 = 5/2 = ratio of shadow length to height

s/36 = 50/20 = 5/2

2s = 36(5)

s= 18(5)

s= 90 meters= shadow length of the tree 36 meters high