Business A garage mechanic purchases oil in a 50- gallon container for changing oil in

customers’ cars. After 35 oil changes requiring 5 qt each, how much oil is left in the 50-
gallon container?
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1 answer

To determine how much oil is left in the 50-gallon container after 35 oil changes, we first need to calculate the total amount of oil used for the changes.

  1. Calculate the total oil used: Each oil change requires 5 quarts of oil. Therefore, for 35 oil changes:

    \[ \text{Total oil used} = 35 \text{ changes} \times 5 \text{ quarts/change} = 175 \text{ quarts} \]

  2. Convert gallons to quarts: Since 1 gallon is equal to 4 quarts, we can convert the initial 50 gallons to quarts:

    \[ \text{Initial oil in quarts} = 50 \text{ gallons} \times 4 \text{ quarts/gallon} = 200 \text{ quarts} \]

  3. Calculate the remaining oil: Now we subtract the total oil used from the initial amount:

    \[ \text{Remaining oil} = 200 \text{ quarts} - 175 \text{ quarts} = 25 \text{ quarts} \]

  4. Convert the remaining oil back to gallons (if needed): To find the remaining oil in gallons:

    \[ \text{Remaining oil in gallons} = \frac{25 \text{ quarts}}{4 \text{ quarts/gallon}} = 6.25 \text{ gallons} \]

Thus, after 35 oil changes, the amount of oil left in the 50-gallon container is 25 quarts or 6.25 gallons.