Jeremy had 6 times as many erasers as Fabian at first. Then each of them bought an equal number of new erasers. In the end, Fabian had 45 erasers and Jeremy had 5 times as many erasers as Fabian. How many erasers did both of them buy altogether?
| |
Jeremy |
Fabian |
Difference |
| Before |
6x4 =
24 u |
1x4 =
4 u |
5x4 =
20 u |
| Change |
+ ? |
+ ? |
|
| After |
5x5 =
25 u |
1x5 =
5 u |
4x5 =
20 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 5 and 4 is 20.
Number of erasers that Fabian had in the end = 5 u
5 u = 45
1 u = 45 ÷ 5 = 9
Number of erasers that Jeremy bought
= 25 u - 24 u
= 1 u
Number of erasers that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 9
= 18
Answer(s): 18
