Box M contains 2 blue balls and 4 green balls. Box N contains 44 blue balls and 16 green balls. How many green balls and blue balls must be removed from Box N to put into Box M so that 50% of the balls in Box A are blue and 75% of the balls in Box N are blue?
|
Box M |
Box N |
|
Blue balls |
Green balls |
Blue balls |
Green balls |
Before |
2 |
4 |
44 |
16 |
Change |
+ ? |
+ ? |
- ? |
- ? |
After |
1 u |
1 u |
3 p |
1 p |
50% =
50100 = 12
75% =
75100 = 34
Number of blue balls = 2 + 44 = 46
Number of green balls = 4 + 16 = 20
1 u + 3 p = 46 --- (1)
1 u + 1 p = 20 ---(2)
(1) - (2)
(1 u + 3 p) - (1 u + 1 p) = 46 - 20
3 p - 1 p = 26
2 p = 26
1 p = 26 ÷ 2 = 13
From (2):
1 u + 1 p = 20
1 u + 1 x 13 = 20
1 u + 13 = 20
1 u = 20 - 13 = 7
Number of green balls to be removed from Box N to Box M
= 16 - 1 p
= 16 - 1 x 13
= 16 - 13
= 3
Number of blue balls to be removed from Box N to Box M
= 1 u - 2
= 7 - 2
= 5
Total number of green and blue balls to be removed from Box N to Box M
= 3 + 5
= 8
Answer(s): 8