Julian, Brandon and Ivan had a total of 58 pens. The ratio of the number of pens that Brandon had to the number of pens that Ivan had was 4 : 9. After Julian and Brandon each gave away half of their pens, the 3 children had 47 pens left. How many pens did Brandon and Ivan have in the end?
| |
Julian |
Brandon |
Ivan |
Total |
| Before |
2 p |
4 u |
9 u |
58 |
| Change |
- 1 p |
- 2 u |
|
- 11 |
| After |
1 p |
2 u |
9 u |
47 |
Total number of pens that Julian and Brandon gave away
= 58 - 47
= 11
1 p + 2 u = 11 --- (1)
1 p + 2 u + 9 u = 47
1 p + 11 u = 47 --- (2)
(2) - (1)
(1 p + 11 u) - (1 p + 2 u) = 47 - 11
11 u - 2 u = 36
9 u = 36
1 u = 36 ÷ 9 = 4
Total number of pens that Brandon and Ivan had in the end
= 2 u + 9 u
= 11 u
= 11 x 4
= 44
Answer(s): 44
