David, Warren and Peter had 320 stickers. After David used 17 stickers and Warren used
15 of her stickers, David had thrice as many stickers left as Warren. Peter bought another 27 stickers, he had four times the number of stickers Warren had left. How many stickers did Peter have at first?
| |
David |
Warren |
Peter |
Total |
| Before |
12 u + 17 |
5 u |
16 u - 27 |
320 |
| Change |
- 17 |
- 1 u |
+ 27 |
|
| After |
12 u |
4 u |
16 u |
|
Comparing David
and Warren in the end |
3 |
1 |
|
|
Comparing Peter
and Warren in the end |
|
1 |
4 |
|
Number of stickers that David had in the end
= 3 x 4 u
= 12 u
Number of stickers that Peter had in the end
= 4 x 4 u
= 16 u
Total number of stickers at first
= 12 u + 17 + 5 u + 16 u - 27
= 33 u - 10
33 u - 10 = 320
33 u = 320 + 10
33 u = 330
1 u = 330 ÷ 33 = 10
Number of stickers that Peter had at first
= 16 u - 27
= 16 x 10 - 27
= 160 - 27
= 133
Answer(s): 133
