Simon, Brandon and Ryan had 205 pens. After Simon used 20 pens and Brandon used
27 of her pens, Simon had thrice as many pens left as Brandon. Ryan bought another 25 pens, he had four times the number of pens Brandon had left. How many pens did Ryan have at first?
| |
Simon |
Brandon |
Ryan |
Total |
| Before |
15 u + 20 |
7 u |
20 u - 25 |
205 |
| Change |
- 20 |
- 2 u |
+ 25 |
|
| After |
15 u |
5 u |
20 u |
|
Comparing Simon
and Brandon in the end |
3 |
1 |
|
|
Comparing Ryan
and Brandon in the end |
|
1 |
4 |
|
Number of pens that Simon had in the end
= 3 x 5 u
= 15 u
Number of pens that Ryan had in the end
= 4 x 5 u
= 20 u
Total number of pens at first
= 15 u + 20 + 7 u + 20 u - 25
= 42 u - 5
42 u - 5 = 205
42 u = 205 + 5
42 u = 210
1 u = 210 ÷ 42 = 5
Number of pens that Ryan had at first
= 20 u - 25
= 20 x 5 - 25
= 100 - 25
= 75
Answer(s): 75
