Hilda and Kathy have some biscuits each. If Hilda gives Kathy 38 biscuits, Hilda will have
12 as many biscuits as Kathy. If Hilda gives Kathy 9 biscuits, they will have an equal number of biscuits. How many biscuits does Kathy have at first?
|
Case 1 |
Case 2 |
|
Hilda |
Kathy |
Hilda |
Kathy |
Before |
1 u + 38 |
2 u - 38 |
1.5 u + 9 |
1.5 u - 9 |
Change |
- 38 |
+ 38 |
- 9 |
+ 9 |
After |
1 u |
2 u |
1.5 u |
1.5 u |
Total number of biscuits that Hilda and Kathy have
= 1 u + 2 u
= 3 u
Number of biscuits that Hilda and Kathy each has in the end is the same.
Number of biscuits that Hilda and Kathy each has in the end in Case 2
= 3 u ÷ 2
= 1.5 u
Number of biscuits that Hilda had at first is the same in Case 1 and Case 2.
1.5 u + 9 = 1 u + 38
1.5 u - 1 u = 38 - 9
0.5 u = 29
1 u = 29 ÷ 0.5 = 58
Number of biscuits that Kathy has
= 2 u - 38
= 2 x 58 - 38
= 116 - 38
= 78
Answer(s): 78