Fiona has a bag containing some gold and orange cards. If she removes 14 gold cards, 40% of the cards in the bag are orange. If she removes another 20 orange cards, 10% of the cards in the bag are orange. How many gold cards are in the bag?
| |
Gold cards |
Orange cards |
| Before |
9 u + 14 |
6 u |
| Change 1 |
- 14 |
|
| After 1 |
3x3 =
9 u |
2x3 =
6 u |
| Change 2 |
|
- 20 |
| After 2 |
9x1 =
9 u |
1x1 =
1 u |
40% =
40100 =
2510% =
10100 =
110The number of gold cards remains unchanged at the second change when she removes another 20 orange cards. Make the number of gold cards the same at the second change. LCM of 3 and 9 is 9.
Number of orange cards removed
= 6 u - 1 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Number of gold cards at first
= 9 u + 14
= 9 x 4 + 14
= 36 + 14
= 50
Answer(s): 50
