Andy, Oscar and Ken had a total of 61 stickers. The ratio of the number of stickers that Oscar had to the number of stickers that Ken had was 8 : 7. After Andy and Oscar each gave away half of their stickers, the 3 children had 41 stickers left. How many stickers did Oscar and Ken have in the end?
| |
Andy |
Oscar |
Ken |
Total |
| Before |
2 p |
8 u |
7 u |
61 |
| Change |
- 1 p |
- 4 u |
|
- 20 |
| After |
1 p |
4 u |
7 u |
41 |
Total number of stickers that Andy and Oscar gave away
= 61 - 41
= 20
1 p + 4 u = 20 --- (1)
1 p + 4 u + 7 u = 41
1 p + 11 u = 41 --- (2)
(2) - (1)
(1 p + 11 u) - (1 p + 4 u) = 41 - 20
11 u - 4 u = 21
7 u = 21
1 u = 21 ÷ 7 = 3
Total number of stickers that Oscar and Ken had in the end
= 4 u + 7 u
= 11 u
= 11 x 3
= 33
Answer(s): 33
