Jen bought thrice as many puffs as Ryan. After Jen ate 3 puffs, she had 7 more puffs than Ryan. How many puffs did they buy altogether?
| |
Jen |
Ryan |
Total |
| Before |
3 u |
1 u |
4 u |
| Change |
- 3 |
|
|
| After |
3 u - 3 |
1 u |
|
The number of puffs that Ryan had remains unchanged.
If Ryan had another 7 puffs in the end, the number of puffs that Jen and Ryan had would be the same.
3 u - 3 = 1 u + 7
3 u - 1 u = 7 + 3
2 u = 10
1 u = 10 ÷ 2 = 5
Total number of puffs
= 3 u + 1 u
= 4 u
= 4 x 5
= 20
Answer(s): 20
