Charlie, Neave and David had 144 stickers. After Charlie used 9 stickers and Neave used
14 of her stickers, Charlie had thrice as many stickers left as Neave. David bought another 17 stickers, he had twice the number of stickers Neave had left. How many stickers did David have at first?
| |
Charlie |
Neave |
David |
Total |
| Before |
9 u + 9 |
4 u |
6 u - 17 |
144 |
| Change |
- 9 |
- 1 u |
+ 17 |
|
| After |
9 u |
3 u |
6 u |
|
Comparing Charlie
and Neave in the end |
3 |
1 |
|
|
Comparing David
and Neave in the end |
|
1 |
2 |
|
Number of stickers that Charlie had in the end
= 3 x 3 u
= 9 u
Number of stickers that David had in the end
= 2 x 3 u
= 6 u
Total number of stickers at first
= 9 u + 9 + 4 u + 6 u - 17
= 19 u - 8
19 u - 8 = 144
19 u = 144 + 8
19 u = 152
1 u = 152 ÷ 19 = 8
Number of stickers that David had at first
= 6 u - 17
= 6 x 8 - 17
= 48 - 17
= 31
Answer(s): 31
