Lucy had 12 more puffs than Fanny at first. After Lucy ate 4 puffs, she had thrice as many puffs as Fanny in the end. How many puffs did Fanny have?
| |
Fanny |
Lucy |
| Before |
1 u |
1 u + 12 |
| Change |
|
- 4 |
| After |
1 u |
1 u + 8 |
Comparing Fanny
and Lucy in the end |
1 u |
3 u |
The number of puffs that Fanny had remains unchanged.
Number of puffs that Lucy had in the end
= 3 x 1 u
= 3 u
3 u = 1 u + 8
3 u - 1 u = 8
2 u = 8
1 u = 8 ÷ 2 = 4
Number of puffs that Fanny had
= 1 u
= 4
Answer(s): 4
