In a jar, the ratio of the number of yellow beads to the number of red beads was 1 : 4. Each time, 5 yellow and 6 red beads were taken out of the jar. A while later, only 70 red beads were left in the jar. What was the total number of beads in the jar at first?
| |
Yellow beads |
Red beads |
| Before |
1x5 =
5 u |
4x5 =
20 u |
| Change |
- 5 u |
- 6 u |
| After |
0 |
70 |
Since there is no yellow beads left, this means that the number of yellow marbles at first is the same as the number of yellow marbles taken out.
Make the number of yellow beads at first and taken out the same. LCM of 1 and 5 is 5.
Number of red beads in the end
= 20 u - 6 u
= 14 u
14 u = 70
1 u = 70 ÷ 14 = 5
Total number of beads in the jar at first
= 5 u + 20 u
= 25 u
= 25 x 5
= 125
Answer: 125
