Jean has a bag containing some blue and silver beads. If she adds in 15 blue beads, 10% of the beads in the bag are silver. If she adds in another 32 silver beads, 50% of the beads in the bag are silver. How many blue beads are in the bag?
| |
Blue beads |
Silver beads |
| Before |
9 u - 15 |
1 u |
| Change 1 |
+ 15 |
|
| After 1 |
9x1 =
9 u |
1x1 =
1 u |
| Change 2 |
|
+ 32 |
| After 2 |
1x9 =
9 u |
1x9 =
9 u |
10% =
10100 =
11050% =
50100 =
12The number of blue beads remains unchanged at the second change when she adds in another 32 silver beads. Make the number of blue beads the same at the second change. LCM of 9 and 1 is 9.
Number of silver beads added
= 9 u - 1 u
= 8 u
8 u = 32
1 u = 32 ÷ 8 = 4
Number of blue beads at first
= 9 u - 15
= 9 x 4 - 15
= 36 - 15
= 21
Answer(s): 21
