Final answer:
To calculate the total bus fare for Paul and Jonas for a round trip to the fair after the fare increase, multiply the new cost of a single trip (original cost plus $0.25) by 2 for the round trip, then by 2 again for both individuals.
Step-by-step explanation:
To assist Paul and Jonas in determining how much they will have to pay to ride the bus to the fair and back, given that the bus company just raised its fares by $0.25, we can create a formula. First, we need to know the original cost of a single bus trip, which we will call c. Then, we can calculate the new cost of a single trip by adding $0.25 to the original cost, which we represent as c + $0.25. Since they are making a round trip, we will have to multiply the cost of one trip by 2. So, the formula to determine the total fare for both Paul and Jonas will be:
Total Fare = 2 × (c + $0.25) × 2
This includes both the trip to the fair and the return trip for both people. For example, if the original fare was $2.00, the new fare for one trip would be $2.25. Thus, for both Paul and Jonas to make a round trip, it would cost:
Total Fare = 2 × ($2.00 + $0.25) × 2 = 2 × $2.25 × 2 = $9.00
This simple multiplication formula will help them determine their total fare with ease.