Penelope had 18 more wafers than Gillian at first. After Penelope ate 6 wafers, she had thrice as many wafers as Gillian in the end. How many wafers did Gillian have?
| |
Gillian |
Penelope |
| Before |
1 u |
1 u + 18 |
| Change |
|
- 6 |
| After |
1 u |
1 u + 12 |
Comparing Gillian
and Penelope in the end |
1 u |
3 u |
The number of wafers that Gillian had remains unchanged.
Number of wafers that Penelope had in the end
= 3 x 1 u
= 3 u
3 u = 1 u + 12
3 u - 1 u = 12
2 u = 12
1 u = 12 ÷ 2 = 6
Number of wafers that Gillian had
= 1 u
= 6
Answer(s): 6
