Tina and Erika have some files in the ratio 3 : 11. Tina has 72 less files than Erika. How many files must Erika give to Tina so that they will have the same number of files?
| |
Tina |
Erika |
Total |
| Before |
3 u |
11 u |
14 u |
| Change |
+ 4 u |
- 4 u |
|
After |
1x7 =
7 u |
1x7 =
7 u |
2x7 =
14 u |
The total number of files remains unchanged. Make the total number of files at first and in the end the same. LCM of 2 and 14 is 14.
Difference in the number of files at first
= 11 u - 3 u
= 8 u
8 u = 72
1 u = 72 ÷ 8 = 9
Number of files that each of them had in the end
= 14 u ÷ 2
= 7 u
Number of files that Erika must give to Tina
= 7 u - 3 u
= 4 u
= 4 x 9
= 36
Answer(s): 36
