Tommy had 5 times as many cards as Julian at first. Then each of them bought an equal number of new cards. In the end, Julian had 16 cards and Tommy had 4 times as many cards as Julian. How many cards did both of them buy altogether?
| |
Tommy |
Julian |
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 Julian had in the end = 4 u
4 u = 16
1 u = 16 ÷ 4 = 4
Number of cards that Tommy bought
= 16 u - 15 u
= 1 u
Number of cards that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 4
= 8
Answer(s): 8
