Paul had 5 times as many beads as Peter at first. Then each of them bought an equal number of new beads. In the end, Peter had 20 beads and Paul had 3 times as many beads as Peter. How many beads did both of them buy altogether?
| |
Paul |
Peter |
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 beads at first and in the end remains unchanged. Make the difference in the number of beads at first and in the end the same. LCM of 4 and 2 is 4.
Number of beads that Peter had in the end = 2 u
2 u = 20
1 u = 20 ÷ 2 = 10
Number of beads that Paul bought
= 6 u - 5 u
= 1 u
Number of beads that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 10
= 20
Answer(s): 20
