In a jar, the ratio of the number of red beads to the number of yellow beads was 1 : 3. Each time, 3 red and 7 yellow beads were taken out of the jar. A while later, only 88 yellow beads were left in the jar. What was the total number of beads in the jar at first?
| |
Red beads |
Yellow beads |
| Before |
1x3 =
3 u |
3x3 =
9 u |
| Change |
- 3 u |
- 7 u |
| After |
0 |
88 |
Since there is no red beads left, this means that the number of red marbles at first is the same as the number of red marbles taken out.
Make the number of red beads at first and taken out the same. LCM of 1 and 3 is 3.
Number of yellow beads in the end
= 9 u - 7 u
= 2 u
2 u = 88
1 u = 88 ÷ 2 = 44
Total number of beads in the jar at first
= 3 u + 9 u
= 12 u
= 12 x 44
= 528
Answer: 528
