In a pouch, the ratio of the number of gold beads to the number of grey beads was 1 : 3. Each time, 3 gold and 6 grey beads were taken out of the pouch. A while later, only 141 grey beads were left in the pouch. What was the total number of beads in the pouch at first?
| |
Gold beads |
Grey beads |
| Before |
1x3 =
3 u |
3x3 =
9 u |
| Change |
- 3 u |
- 6 u |
| After |
0 |
141 |
Since there is no gold beads left, this means that the number of gold marbles at first is the same as the number of gold marbles taken out.
Make the number of gold beads at first and taken out the same. LCM of 1 and 3 is 3.
Number of grey beads in the end
= 9 u - 6 u
= 3 u
3 u = 141
1 u = 141 ÷ 3 = 47
Total number of beads in the pouch at first
= 3 u + 9 u
= 12 u
= 12 x 47
= 564
Answer: 564
