Questions: Bob's Auto Parts were currently 15 new cars, 9 new trucks, and 3 used trucks. Bob spent 10 hours on each new car, 8 hours on each new truck, and 4 hours on each used truck. Do not round intermediate computations, and round your answer to the nearest hundredth. The total of the hours that Bob spends on trucks?

Solution Steps

To find the total hours Bob spent on trucks, we need to calculate the hours spent on new trucks and used trucks separately and then sum them up.

1. Calculate the total hours spent on new trucks by multiplying the number of new trucks by the hours spent on each new truck.
2. Calculate the total hours spent on used trucks by multiplying the number of used trucks by the hours spent on each used truck.
3. Sum the hours from step 1 and step 2 to get the total hours spent on trucks.

The total hours spent on new trucks can be calculated as follows: \[ \text{Total Hours for New Trucks} = \text{new\_trucks} \times \text{hours\_per\_new\_truck} = 9 \times 8 = 72 \]

The total hours spent on used trucks is calculated as: \[ \text{Total Hours for Used Trucks} = \text{used\_trucks} \times \text{hours\_per\_used\_truck} = 3 \times 4 = 12 \]

Now, we sum the hours spent on new trucks and used trucks: \[ \text{Total Hours for Trucks} = \text{Total Hours for New Trucks} + \text{Total Hours for Used Trucks} = 72 + 12 = 84 \]

Final Answer