Ahmad had 6 times as many buttons as Perry at first. Then each of them bought an equal number of new buttons. In the end, Perry had 55 buttons and Ahmad had 5 times as many buttons as Perry. How many buttons did both of them buy altogether?
| |
Ahmad |
Perry |
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 buttons at first and in the end remains unchanged. Make the difference in the number of buttons at first and in the end the same. LCM of 5 and 4 is 20.
Number of buttons that Perry had in the end = 5 u
5 u = 55
1 u = 55 ÷ 5 = 11
Number of buttons that Ahmad bought
= 25 u - 24 u
= 1 u
Number of buttons that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 11
= 22
Answer(s): 22
