Sam has 10% as many cards as Albert. If Sam gives away 20% of the cards and Albert gives away 90% of his cards, they will have 36 cards altogether. How many cards do the two of them have?
| |
Sam |
Albert |
Total |
Comparing Sam
and Albert at first |
1x5 =
5 u |
10x5 =
50 u |
|
| Before |
5x1 =
5 u |
10x5 =
50 u |
|
| Change |
- 1x1 =
- 1 u |
- 9x5 =
- 45 u |
|
| After |
4x1 =
4 u |
1x5 =
5 u |
36 |
10% =
10100 =
110 20% =
20100 =
15 90% =
90100 =
910 The number of cards that Sam has at first is repeated. Make the number of cards that Sam has the same. LCM of 1 and 5 is 5 u.
The number of cards that Albert has at first is repeated. Make the number of cards that Albert has the same. LCM of 10 and 10 is 50 u.
Number of cards in the end
= 4 u + 5 u
= 9 u
9 u = 36
1 u = 36 ÷ 9 = 4
Total number of cards that the two of them have
= 5 u + 50 u
= 55 u
= 55 x 4
= 220
Answer(s): 220
