Peter had an equal number of strawberry cookies, blueberry cookies and vanila cookies. After he ate 40 strawberry cookies, some blueberry cookies and vanila cookies, there were 68 cookies left. The number of blueberry cookies he ate was twice the number of vanila cookies he ate. The number of blueberry cookies left was 22 more than the number of strawberry cookies left. How many strawberry cookies were there at first?
| |
Strawberry cookies |
Blueberry cookies |
Vanila cookies |
Total cookies |
| Before |
1 p + 40 |
1 p + 2 u + 22 |
1 p + 2 u + 22 |
|
| Change |
- 40 |
- 2 u |
- 1 u |
|
| After |
1 p |
1 p + 22 |
1 p + 22 + 1 u |
68 |
Number of blueberry cookies and strawberry cookies was equal at first.
1 p + 2 u + 22 = 1 p + 40
2 u = 40 - 22
2 u = 18
1 u = 18 ÷ 2 = 9
Total number of cookies in the end
= 1 p + 1 p + 22 + 1 p + 22 + 9
= 1 p + 1 p + 1 p + 22 + 22 + 9
= 3 p + 53
3 p + 53 = 68
3 p = 68 - 53
3 p = 15
1 p = 15 ÷ 3 = 5
Number of strawberry cookies at first
= 1 p + 40
= 5 + 40
= 45
Answer(s): 45
