Yoko has a bag containing some silver and pink beads. If she removes 20 silver beads, 40% of the beads in the bag are pink. If she removes another 60 pink beads, 30% of the beads in the bag are pink. How many silver beads are in the bag?
| |
Silver beads |
Pink beads |
| Before |
21 u + 20 |
14 u |
| Change 1 |
- 20 |
|
| After 1 |
3x7 =
21 u |
2x7 =
14 u |
| Change 2 |
|
- 60 |
| After 2 |
7x3 =
21 u |
3x3 =
9 u |
40% =
40100 =
2530% =
30100 =
310The number of silver beads remains unchanged at the second change when she removes another 60 pink beads. Make the number of silver beads the same at the second change. LCM of 3 and 7 is 21.
Number of pink beads removed
= 14 u - 9 u
= 5 u
5 u = 60
1 u = 60 ÷ 5 = 12
Number of silver beads at first
= 21 u + 20
= 21 x 12 + 20
= 252 + 20
= 272
Answer(s): 272
