Liam had 5 times as many erasers as Carl at first. Then each of them bought an equal number of new erasers. In the end, Carl had 4 erasers and Liam had 3 times as many erasers as Carl. How many erasers did both of them buy altogether?
| |
Liam |
Carl |
Difference |
| Before |
5x1 =
5 u |
1x1 =
1 u |
4x1 =
4 u |
| Change |
+ ? |
+ ? |
|
| After |
3x2 =
6 u |
1x2 =
2 u |
2x2 =
4 u |
The difference in the number of erasers at first and in the end remains unchanged. Make the difference in the number of erasers at first and in the end the same. LCM of 4 and 2 is 4.
Number of erasers that Carl had in the end = 2 u
2 u = 4
1 u = 4 ÷ 2 = 2
Number of erasers that Liam bought
= 6 u - 5 u
= 1 u
Number of erasers that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 2
= 4
Answer(s): 4
