Risa has 4 times as many cards as Erika. Erika has
37 as many cards as Mary. If the three of them have a total of 198 cards, how many cards does Mary have?
Risa |
Erika |
Mary |
4x3 |
1x3 |
|
|
3x1 |
7x1 |
12 u |
3 u |
7 u |
The number of cards that Erika has is repeated. Make the number of cards that Erika has the same. LCM of 1 and 3 is 3.
Total number of cards that the three of them have
= 12 u + 3 u + 7 u
= 22 u
22 u = 198
1 u = 198 ÷ 22 = 9
Number of cards that Mary has
= 7 u
= 7 x 9
= 63
Answer(s): 63