Natalie had four containers, F, G, H and J which contained a total of 206 starfruits. She transferred 20 starfruits from Container F to Container G, 42 starfruits from Container G to Container H and 68 starfruits from Container H to Container J. The ratio of the number of starfruits in Container F to Container G to Container H changed from 4 : 7 : 9 to 1 : 5 : 7. How many starfruits were in Container J at first?
|
Make p the same (1)x5 = (3) |
F (1) |
G (2) |
H
|
J
|
Before |
20 u |
4 u |
7 u |
9 u |
? |
Change 1 |
- 100 |
- 20 |
+ 20 |
|
|
Change 2 |
|
|
- 42 |
+ 42 |
|
Change 3 |
|
|
|
- 68 |
+ 68 |
After |
5 p |
1 p |
5 p |
7 p |
? |
4 u - 20 = 1 p --- (1)
7 u + 20 - 42 = 5 p
7 u - 22 =
5 p --- (2)
(1)
x 5 20 u - 100 =
5 p --- (3)
Make p the same.
(3) = (2)
20 u - 100 = 7 u - 22
20 u - 7 u = 100 - 22
13 u = 78
1 u = 78 ÷ 13 = 6
Total number of starfruits in Container F, Container G and Container H
= 4 u + 7 u + 9 u
= 20 u
Total number of starfruits in Container J at first
= 206 - 20 u
= 206 - 20 x 6
= 206 - 120
= 86
Answer(s): 86