Anna bought thrice as many puffs as Luis. After Anna ate 7 puffs, she had 9 more puffs than Luis. How many puffs did they buy altogether?
| |
Anna |
Luis |
Total |
| Before |
3 u |
1 u |
4 u |
| Change |
- 7 |
|
|
| After |
3 u - 7 |
1 u |
|
The number of puffs that Luis had remains unchanged.
If Luis had another 9 puffs in the end, the number of puffs that Anna and Luis had would be the same.
3 u - 7 = 1 u + 9
3 u - 1 u = 9 + 7
2 u = 16
1 u = 16 ÷ 2 = 8
Total number of puffs
= 3 u + 1 u
= 4 u
= 4 x 8
= 32
Answer(s): 32
