PSLE Mary had an equal number of blue and silver beads. She gave 31 blue beads and 27 silver beads to Mary. She gave the remaining beads to Nora. Nora was given 4 blue beads for every 6 silver beads. How many beads did Mary have at first?
|
Blue |
Silver |
Before |
4 u + 31 |
6 u + 27 |
Change |
- 31 |
- 27 |
After |
4 u |
6 u |
The number of blue and silver beads is equal at first.
4 u + 31 = 6 u + 27
6 u - 4 u = 31 - 27
2 u = 4
1 u = 4 ÷ 2 = 2
Number of blue beads that Mary had at first
= 4 u + 31
= 4 x 2 + 31
= 8 + 31
= 39
Number of beads that Mary had at first
= 2 x 39
= 78
Answer(s): 78