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