Answer: $18.75
Step-by-step explanation:
1 - 3/8 = 5/8
12 x 5/8 = 7.5
7.5 x 2.5 = 18.75
Dave spent $18.75, in filling his car's tank of capacity 12 gallons up to the capacity, which was 3/8th filled already, at the unit rate of $2.50 per gallon of gas.
The unit rate is the quantity (cost/distance/time, etc.) for one unit of another quantity (cost/distance/time, etc.).
In the question, we are informed that the gas tank of Dave's car has a capacity of 12 gallons. The tank was 3/8 full before Dave filled it to capacity. It cost him $2.50 per gallon of gas.
We are asked the amount Dave spent.
The unit rate of gas is $2.50 per gallon.
To find the total amount spent by Dave, we need to find the volume of gas he filled and then multiply that volume with the unit rate.
The capacity of Dave's car's tank = 12 gallons.
Gas it already had = 3/8th of capacity,
or, gas it already had = 3/8 * 12 = 4.5 gallons.
Therefore, the volume of gas Dave filled = 12 - 4.5 gallons = 7.5 gallons.
The amount spent by Dave = Volume filled*Unit rate = $ 7.5 * 2.5 = $18.75.
Therefore, Dave spent $18.75, in filling his car's tank of capacity 12 gallons up to the capacity, which was 3/8th filled already, at the unit rate of $2.50 per gallon of gas.
Learn more about unit rates at
https://brainly.com/question/13994187
#SPJ2
