## alainabbyboo22 3 years ago At a certain time of day, a 5 foot tall man has a 7.5 foot shadow. If a tree is 20 feet tall, what is the length of the shadow of the tree?

1. alainabbyboo22

2. alainabbyboo22

A. 30 feet B. 12 feet C. 24 feet D. 15 feet

3. alainabbyboo22

or at least could someone tell me what i need to do to find my answer ? do i multiply to get the length ? divide ?

4. Chlorophyll

Apply ratio with S is the length of the tree shadow: S/ 20 = 7.5 / 5 => S = ...? @alainabbyboo22 Can you continue?

5. alainabbyboo22

what is "S" supposed to be ? i don't get this ..

6. ganeshie8

Shadow its same as x in ur pix

7. alainabbyboo22

oh okay . but no , i'm unable to continue because i'm unsure of how to do this . /:

8. ganeshie8

$$\frac{S}{20} = \frac{7.5}{5}$$ you need to solve S

9. ganeshie8

for that you need to isolate S, multiply 20 both sides

10. alainabbyboo22

S/400 = 150/S

11. alainabbyboo22

correct or incorrect ?

12. Chlorophyll

You divide it :(

13. ganeshie8

$$\frac{S}{20} = \frac{7.5}{5}$$ multiply 20 both sides $$20*\frac{S}{20} = 20*\frac{7.5}{5}$$

14. ganeshie8

does 20 cancel on left side ?

15. ganeshie8

$$\cancel{20}*\frac{S}{\cancel{20}} = 20*\frac{7.5}{5}$$

16. ganeshie8

simplify right side

17. Chlorophyll

@alainabbyboo22 Learn to multiply, will you !