Final answer:
The unit rate for miles per gallon is 28 2/5 miles per gallon.
Step-by-step explanation:
The unit rate for miles per gallon is found by dividing the number of miles driven by the number of gallons of gasoline used. In this case, Jack drove 35 1/2 miles and used 1 1/4 gallons of gasoline. To find the unit rate, we divide 35 1/2 by 1 1/4. First, convert the mixed numbers to improper fractions: 35 1/2 = 71/2 and 1 1/4 = 5/4.
Then, divide 71/2 by 5/4: 71/2 ÷ 5/4 = 71/2 * 4/5 = (71*4)/(2*5) = 284/10 = 28 4/10 = 28 2/5. Therefore, the unit rate for miles per gallon is 28 2/5 miles per gallon.