There are some yellow and pink balls in a container. If 5 yellow balls are removed from the container, the total number of balls left will be 8 times the number of yellow balls left. If 35 pink balls are removed from the container, the total number of balls left will be 3 times the number of yellow balls. How many balls are there in the container?
|
Case 1 |
Case 2 |
|
Yellow balls |
Pink balls |
Yellow balls |
Pink balls |
Before |
1 u + 5 |
7 u |
1 p |
2 p + 35 |
Change |
- 5 |
|
|
- 35 |
After |
1 u |
7 u |
1 p |
2 p |
Number of pink balls in the end for Case 1
= 8 u - 1 u
= 7 u
Number of yellow balls in the end for Case 2
= 3 p - 1 p
= 2 p
The number of yellow balls at first is the same for Case 1 and Case 2.
The number of pink balls at first is also the same for Case 1 and Case 2.
1 u + 5 = 1 p --- (1)
7 u = 2 p + 35
7 u - 35 =
2 p --- (2)
Make p the same.
(1)
x2 2 u + 10 =
2 p --- (3)
(2) = (3)
7 u - 35 = 2 u + 10
7 u - 2 u = 10 + 35
5 u = 45
1 u = 45 ÷ 5 = 9
Number of balls in the container
= (1 u + 5) + 7 u
= 8 u + 5
= (8 x 9) + 5
= 72 + 5
= 77
Answer(s): 77