Pamela and Barbara have some pencils in the ratio 3 : 7. Pamela has 48 less pencils than Barbara. How many pencils must Barbara give to Pamela so that they will have the same number of pencils?
| |
Pamela |
Barbara |
Total |
| Before |
3 u |
7 u |
10 u |
| Change |
+ 2 u |
- 2 u |
|
After |
1x5 =
5 u |
1x5 =
5 u |
2x5 =
10 u |
The total number of pencils remains unchanged. Make the total number of pencils at first and in the end the same. LCM of 2 and 10 is 10.
Difference in the number of pencils at first
= 7 u - 3 u
= 4 u
4 u = 48
1 u = 48 ÷ 4 = 12
Number of pencils that each of them had in the end
= 10 u ÷ 2
= 5 u
Number of pencils that Barbara must give to Pamela
= 5 u - 3 u
= 2 u
= 2 x 12
= 24
Answer(s): 24
