Fabian had an equal number of cream biscuits, butter biscuits and vanila biscuits. After he ate 47 cream biscuits, some butter biscuits and vanila biscuits, there were 70 biscuits left. The number of butter biscuits he ate was thrice the number of vanila biscuits he ate. The number of butter biscuits left was 20 more than the number of cream biscuits left. How many cream biscuits were there at first?
| |
Cream biscuits |
Butter biscuits |
Vanila biscuits |
Total biscuits |
| Before |
1 p + 47 |
1 p + 3 u + 20 |
1 p + 3 u + 20 |
|
| Change |
- 47 |
- 3 u |
- 1 u |
|
| After |
1 p |
1 p + 20 |
1 p + 20 + 1 u |
70 |
Number of butter biscuits and cream biscuits was equal at first.
1 p + 3 u + 20 = 1 p + 47
3 u = 47 - 20
3 u = 27
1 u = 27 ÷ 3 = 9
Total number of biscuits in the end
= 1 p + 1 p + 20 + 1 p + 20 + 9
= 1 p + 1 p + 1 p + 20 + 20 + 9
= 3 p + 49
3 p + 49 = 70
3 p = 70 - 49
3 p = 21
1 p = 21 ÷ 3 = 7
Number of cream biscuits at first
= 1 p + 47
= 7 + 47
= 54
Answer(s): 54
