Xuan had 120 markers.
45 of them were black markers and the rest were grey markers. After she had given away some black markers, the ratio of the number of black markers to the number of grey markers became 7 : 8. How many markers did she have in the end?
| |
Black |
Grey |
Total |
| Before |
4x8 =
32 u |
1x8 =
8 u |
5x8 =
40 u |
| Change |
- 25 u |
|
|
| After |
7 u |
8 u |
15 u |
The number of grey markers remained unchanged.
LCM of 1 and 8 = 8
Total number of markers at first = 40 u
40 u = 120
1 u = 120 ÷ 40 = 3
Number of markers that Xuan had in the end
= 7 u + 8 u
= 15 u
= 15 x 3
= 45
Answer(s):45
