Neave had 6 times as many cards as Sam at first. Then each of them bought an equal number of new cards. In the end, Sam had 30 cards and Neave had 3 times as many cards as Sam. How many cards did both of them buy altogether?
| |
Neave |
Sam |
Difference |
| Before |
6x2 =
12 u |
1x2 =
2 u |
5x2 =
10 u |
| Change |
+ ? |
+ ? |
|
| After |
3x5 =
15 u |
1x5 =
5 u |
2x5 =
10 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 5 and 2 is 10.
Number of cards that Sam had in the end = 5 u
5 u = 30
1 u = 30 ÷ 5 = 6
Number of cards that Neave bought
= 15 u - 12 u
= 3 u
Number of cards that both of them bought altogether
= 2 x 3 u
= 6 u
= 6 x 6
= 36
Answer(s): 36
