Reggie has 70% as many cards as Billy. If Reggie gives away 20% of the cards and Billy gives away 30% of his cards, they will have 441 cards altogether. How many cards do the two of them have?
| |
Reggie |
Billy |
Total |
Comparing Reggie
and Billy at first |
7x5 =
35 u |
10x5 =
50 u |
|
| Before |
5x7 =
35 u |
10x5 =
50 u |
|
| Change |
- 1x7 =
- 7 u |
- 3x5 =
- 15 u |
|
| After |
4x7 =
28 u |
7x5 =
35 u |
441 |
70% =
70100 =
710 20% =
20100 =
15 30% =
30100 =
310 The number of cards that Reggie has at first is repeated. Make the number of cards that Reggie has the same. LCM of 7 and 5 is 35 u.
The number of cards that Billy has at first is repeated. Make the number of cards that Billy has the same. LCM of 10 and 10 is 50 u.
Number of cards in the end
= 28 u + 35 u
= 63 u
63 u = 441
1 u = 441 ÷ 63 = 7
Total number of cards that the two of them have
= 35 u + 50 u
= 85 u
= 85 x 7
= 595
Answer(s): 595
