Abi had four boxes, N, P, Q and R which contained a total of 262 starfruits. She transferred 10 starfruits from Box N to Box P, 30 starfruits from Box P to Box Q and 54 starfruits from Box Q to Box R. The ratio of the number of starfruits in Box N to Box P to Box Q changed from 3 : 7 : 10 to 1 : 4 : 8. How many starfruits were in Box R at first?
|
Make p the same (1)x4 = (3) |
N (1) |
P (2) |
Q
|
R
|
Before |
12 u |
3 u |
7 u |
10 u |
? |
Change 1 |
- 40 |
- 10 |
+ 10 |
|
|
Change 2 |
|
|
- 30 |
+ 30 |
|
Change 3 |
|
|
|
- 54 |
+ 54 |
After |
4 p |
1 p |
4 p |
8 p |
? |
3 u - 10 = 1 p --- (1)
7 u + 10 - 30 = 4 p
7 u - 20 =
4 p --- (2)
(1)
x 4 12 u - 40 =
4 p --- (3)
Make p the same.
(3) = (2)
12 u - 40 = 7 u - 20
12 u - 7 u = 40 - 20
5 u = 20
1 u = 20 ÷ 5 = 4
Total number of starfruits in Box N, Box P and Box Q
= 3 u + 7 u + 10 u
= 20 u
Total number of starfruits in Box R at first
= 262 - 20 u
= 262 - 20 x 4
= 262 - 80
= 182
Answer(s): 182