Archie had 6 times as many stamps as Xavier at first. Then each of them bought an equal number of new stamps. In the end, Xavier had 10 stamps and Archie had 4 times as many stamps as Xavier. How many stamps did both of them buy altogether?
| |
Archie |
Xavier |
Difference |
| Before |
6x3 =
18 u |
1x3 =
3 u |
5x3 =
15 u |
| Change |
+ ? |
+ ? |
|
| After |
4x5 =
20 u |
1x5 =
5 u |
3x5 =
15 u |
The difference in the number of stamps at first and in the end remains unchanged. Make the difference in the number of stamps at first and in the end the same. LCM of 5 and 3 is 15.
Number of stamps that Xavier had in the end = 5 u
5 u = 10
1 u = 10 ÷ 5 = 2
Number of stamps that Archie bought
= 20 u - 18 u
= 2 u
Number of stamps that both of them bought altogether
= 2 x 2 u
= 4 u
= 4 x 2
= 8
Answer(s): 8
