Esther has a bag containing some purple and pink marbles. If she removes 14 purple marbles, 20% of the marbles in the bag are pink. If she adds another 25 pink marbles, 40% of the marbles in the bag are pink. How many purple marbles are in the bag?
| |
Purple marbles |
Pink marbles |
| Before |
12 u + 14 |
3 u |
| Change 1 |
- 14 |
|
| After 1 |
4x3 =
12 u |
1x3 =
3 u |
| Change 2 |
|
+ 25 |
| After 2 |
3x4 =
12 u |
2x4 =
8 u |
20% =
20100 =
1540% =
40100 =
25The number of purple marbles remains unchanged at the second change when she adds another 25 pink marbles. Make the number of purple marbles the same at the second change. LCM of 4 and 3 is 12.
Number of pink marbles added
= 8 u - 3 u
= 5 u
5 u = 25
1 u = 25 ÷ 5 = 5
Number of purple marbles at first
= 12 u + 14
= 12 x 5 + 14
= 60 + 14
= 74
Answer(s): 74
