Riordan and Billy had the same number of cards. Riordan gave away
45 of his cards while Billy gave away
23 of his cards. Given that Riordan gave away 12 cards more than Billy, how many cards did Riordan have at first?
| |
Riordan's cards |
Billy's cards |
| Before |
5x3 =
15 u |
3x5 =
15 u |
| Change |
- 4x3 =
- 12 u |
- 2x5 =
- 10 u |
| After |
1x3 =
3 u |
1x5 =
5 u |
The number of cards that Riordan and Billy each had at first is the same. Make the number of cards that Riordan and Billy each had at first the same. LCM of 5 and 3 is 15.
Number of cards that Riordan gave away more than Billy
= 12 u - 10 u
= 2 u
2 u = 12
1 u = 12 ÷ 2 = 6
Number of cards that Riordan had at first
= 15 u
= 15 x 6
= 90
Answer(s): 90
