Chandler bought a new car that gives a mileage of 6.5 when driven at a

Question

Chandler bought a new car that gives a mileage of 6.5 when driven at a constant speed of 45 miles per hour, and a mileage of 5.5 at a constant speed of 35 miles per hour. On 600-mile road trip, the car traveled certain initial part of the trip at 45 miles per hour and the rest at 35 miles per hour. If the car used a total of 100 gallons of gas for this trip, how many miles did the car travel at 45 miles per hour? (Mileage is defined as the number of miles covered per gallon of gas)

A. 162.5
B. 275
C. 325
D. 478.5
E. None

Show Answer

Official Answer

C

A. 162.5
B. 275
C. 325
D. 478.5
E. None

Seb2m02 · Accepted Answer

I have another way to resolve this exercise:

600 miles / 100 gallons -> in average, 6 mpg
It is the middle between 5.5mpg and 6.5mpg written in the statement

It means that 50 gallons have been consumed at 35 mph and 50 gallons at 45 mph

calculation of the distance at 45 mph => 6.5 miles per gallon -> 50 gallons means = 6.5x50=325

gmatophobia · Answer

Assume that Chandler travels ' x ' miles at 45 miles per hour.

Amount of gas used for to travel  x  miles =  \frac{x}{6.5}

Distance traveled at 35 miles per hour =  600-x

Amount of gas used for to travel  (600-x)  miles =  \frac{600-x}{5.5}

\frac{x}{6.5} + \frac{(600 - x)}{5.5} = 100

5.5x + (600 * 6.5) - 6.5x = 100 * 6.5 * 5.5

-x = (100 * 6.5 * 5.5) - (600 * 6.5)

-x = 100 * 6.5 (5.5 - 6)

x = 100 * 6.5 * 0.5

x = 325

Option C

ravi1522 · Answer

Hello ,
Let fuel used by car A with 45MPH as x
6.5*x+5.5(100-x)=600
 so fuel used by car will be 50 ,Hence distance travelled will 50*6.5 =325miles

Hence option C is correct

PSKhore · Answer

Good approach!
Also, if this doesn't click, instead of wasting time in trying to construct equation, making use of the options would be a great idea for this problem!

Chandler bought a new car that gives a mileage of 6.5 when driven at a

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Chandler bought a new car that gives a mileage of 6.5 when driven at a

Prep Toolkit

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