Sarah had 90 more pens than Linda. After Linda gave away
14 of her pens, Sarah had thrice as many pens as Linda. How many pens did Linda have at first?
| |
Sarah |
Linda |
Comparing Sarah
and Linda at first |
90 more |
|
| Before |
9 u |
4 u |
| Change |
|
- 1 u |
| After |
|
3 u |
Comparing Sarah
and Linda in the end |
3x3 =
9 u |
1x3 =
3 u |
The number of pens that Sarah had at first and in the end remains unchanged. Make the number of pens that Sarah had the same. LCM of 9 and 3 is 9.
Number of pens that Sarah had more than Linda at first
= 9 u - 4 u
= 5 u
5 u = 90
1 u = 90 ÷ 5 = 18
Number of pens that Linda had at first
= 4 u
= 4 x 18
= 72
Answer(s): 72
