Tom had 5 times as many buttons as Lee at first. Then each of them bought an equal number of new buttons. In the end, Lee had 12 buttons and Tom had 4 times as many buttons as Lee. How many buttons did both of them buy altogether?
| |
Tom |
Lee |
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 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 4 and 3 is 12.
Number of buttons that Lee had in the end = 4 u
4 u = 12
1 u = 12 ÷ 4 = 3
Number of buttons that Tom bought
= 16 u - 15 u
= 1 u
Number of buttons that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 3
= 6
Answer(s): 6
