Usha has a bag containing some red and orange cards. If she removes 4 red cards, 40% of the cards in the bag are orange. If she removes another 25 orange cards, 20% of the cards in the bag are orange. How many red cards are in the bag?
| |
Red cards |
Orange cards |
| Before |
12 u + 4 |
8 u |
| Change 1 |
- 4 |
|
| After 1 |
3x4 =
12 u |
2x4 =
8 u |
| Change 2 |
|
- 25 |
| After 2 |
4x3 =
12 u |
1x3 =
3 u |
40% =
40100 =
2520% =
20100 =
15The number of red cards remains unchanged at the second change when she removes another 25 orange cards. Make the number of red cards the same at the second change. LCM of 3 and 4 is 12.
Number of orange cards removed
= 8 u - 3 u
= 5 u
5 u = 25
1 u = 25 ÷ 5 = 5
Number of red cards at first
= 12 u + 4
= 12 x 5 + 4
= 60 + 4
= 64
Answer(s): 64
