There were some erasers in Bag W and Bag X. After Neave transferred
15 of the erasers from Bag W to Bag X, the ratio of the number of erasers in Bag W to that in Bag X changed to 3 : 4. Find the ratio of the numbers of erasers in Bag W to the number of erasers in Bag X at first.
|
Bag W |
Bag X |
Before |
5x3 = 15 u |
13 u |
Change |
- 1x3 = - 3 u |
+ 3 u |
After |
4x3 = 12 u |
|
Comparing Bag W and Bag X in the end |
3x4 = 12 u |
4x4 = 16 u |
The number of erasers in Bag W in the end is repeated. Make the number of erasers in Bag W in the end the same. LCM of 4 and 3 is 12.
At first
Bag W : Bag X
15 : 13
Answer(s): 15 : 13