Tina had 135 more pens than Xuan. After Xuan gave away
15 of her pens, Tina had five times as many pens as Xuan. How many pens did Xuan have at first?
| |
Tina |
Xuan |
Comparing Tina
and Xuan at first |
135 more |
|
| Before |
20 u |
5 u |
| Change |
|
- 1 u |
| After |
|
4 u |
Comparing Tina
and Xuan in the end |
5x4 =
20 u |
1x4 =
4 u |
The number of pens that Tina had at first and in the end remains unchanged. Make the number of pens that Tina had the same. LCM of 20 and 5 is 20.
Number of pens that Tina had more than Xuan at first
= 20 u - 5 u
= 15 u
15 u = 135
1 u = 135 ÷ 15 = 9
Number of pens that Xuan had at first
= 5 u
= 5 x 9
= 45
Answer(s): 45
