Petya bought one cake, two cupcakes and three bagels, Apya bought three cakes and a bagel, and Kolya bought six cupcakes. They all paid the same amount of money for purchases. Lena bought two cakes and two bagels. And how many cupcakes could be bought for the same amount spent to her?
Solution
To solve this problem, we need to determine how many cupcakes can be purchased for the same amount that Lena spent, given the prices of each pastry type.
Let's denote the prices:
- The price of one cake as .
- The price of one cupcake as .
- The price of one bagel as .
According to the problem, Petya, Apya, and Kolya all spent the same amount of money, leading to the following equations:
- Petya:
- Apya:
- Kolya:
These equations imply:
We want to find the number of cupcakes Lena could buy with the same amount of money she spent on 2 cakes and 2 bagels:
- Lena:
First, set the expressions for Petya and Apya equal:
Simplifying, we have:
Next, equate the expressions for Petya and Kolya:
Simplifying, we find:
We now express in terms of . Using , substitute into expression for Lena:
Now, relate to . From , substitute to get:
Substitute in Lena's equation:
Finally, equating to the equated amounts , notice:
Thus, Lena could purchase cupcakes for the amount she spent. Therefore, the number of cupcakes Lena could buy is: