Answer: 942
Detailed explanation: this was quite challenging!
Let x denote the count of $5 bills and y signify the count of $10 bills. It can be stated that "the number of $10 bills is twice the number of $5 bills." Thus, y is 2 times x. We can formulate an equation, y = 2x (equation 1). The total value of all bills amounts to $125, allowing us to create another equation: 5*(number of $5 bills) + 10*(number of $10 bills) = 125. That leads to the equation 5(x) + 10(y) = 125 (equation 2). By substituting y = 2x into equation 2, we get 5(x) + 10(2x) = 125. This simplifies to 5x + 20x = 125. Combining like terms yields 25x = 125. Dividing both sides by 25 results in x = 5. By substituting x = 5 in the first equation, we find y = 2(5) = 10. Consequently, there are 5 $5 bills and 10 $10 bills.
The solution is 20 days, found as follows:
Each of the three friends initially makes 4 bags of dough. After 10 days, each of these bags is split into 4 new bags:
3 friends × 4 bags = 12 bags, and 12 bags × 4 = 48 bags
Then in the following 10 days, 48 bags are again divided into 4 bags each:
48 × 4 = 192 bags
Adding the periods: 10 days + 10 days = 20 days
Therefore, 192 bags are created after 20 days.