PSLE Mary had an equal number of gold and green beads. She gave 31 gold beads and 27 green beads to Mary. She gave the remaining beads to Nora. Nora was given 5 gold beads for every 7 green beads. How many beads did Mary have at first?
|
Gold |
Green |
Before |
5 u + 31 |
7 u + 27 |
Change |
- 31 |
- 27 |
After |
5 u |
7 u |
The number of gold and green beads is equal at first.
5 u + 31 = 7 u + 27
7 u - 5 u = 31 - 27
2 u = 4
1 u = 4 ÷ 2 = 2
Number of gold beads that Mary had at first
= 5 u + 31
= 5 x 2 + 31
= 10 + 31
= 41
Number of beads that Mary had at first
= 2 x 41
= 82
Answer(s): 82