Seth had 4 times as many cards as Howard at first. Then each of them bought an equal number of new cards. In the end, Howard had 18 cards and Seth had 3 times as many cards as Howard. How many cards did both of them buy altogether?
| |
Seth |
Howard |
Difference |
| Before |
4x2 =
8 u |
1x2 =
2 u |
3x2 =
6 u |
| Change |
+ ? |
+ ? |
|
| After |
3x3 =
9 u |
1x3 =
3 u |
2x3 =
6 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 3 and 2 is 6.
Number of cards that Howard had in the end = 3 u
3 u = 18
1 u = 18 ÷ 3 = 6
Number of cards that Seth bought
= 9 u - 8 u
= 1 u
Number of cards that both of them bought altogether
= 2 x 1 u
= 2 u
= 2 x 6
= 12
Answer(s): 12
