Ivan had 5 times as many beads as Zeph at first. Then each of them bought an equal number of new beads. In the end, Zeph had 8 beads and Ivan had 4 times as many beads as Zeph. How many beads did both of them buy altogether?
| |
Ivan |
Zeph |
Difference |
| Before |
5x3 =
15 u |
1x3 =
3 u |
4x3 =
12 u |
| Change |
+ ? |
+ ? |
|
| After |
4x4 =
16 u |
1x4 =
4 u |
3x4 =
12 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 3 is 12.
Number of beads that Zeph had in the end = 4 u
4 u = 8
1 u = 8 ÷ 4 = 2
Number of beads that Ivan bought
= 16 u - 15 u
= 1 u
Number of beads that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 2
= 4
Answer(s): 4
