Car Z travels 40 miles per gallon of gasoline when driven at a constan

Question

Tough and Tricky questions: Distance/Rate Problems.

Car Z travels 40 miles per gallon of gasoline when driven at a constant rate of 45 miles per hour, but travels 20 percent fewer miles per gallon of gasoline when driven at a constant rate of 60 miles per hour. How many miles does car Z travel on 10 gallons of gasoline when driven at a constant rate of 60 miles per hour?

A. 320
B. 375.2
C. 400
D. 408.3
E. 440

Kudos for a correct  solution .

littlewarthog · Answer

The question stem asks us for the distance possible with 10 gallons of fuel at a constant speed of 60 miles per hour. We therefore first calculate the fuel efficiency at that speed.

The stem tells us that at 45 miles/hour, the car will run 40 miles/gallon and at 60 miles/hour, that distance decreases by 20%. We can therefore conclude that the car will travel 32miles/gallon at a constant speed of 60 miles/gallon. With 10 gallons of fuel, the car can therefore travel 32miles/gallon * 10 gallons = 320 miles.

Answer A.

g106 · Answer

When Driven on 60 miles per hours gas mileage = 32 (80% of 40)
with 10 gallons of gas CAR Z can travel 320 miles

ANs A

qw1981 · Answer

at 60 miles/hour, efficiency= 40- 20%0f40= 0.8*40=32 miles/galon

Hence when car drives at 60m/hr for 10 gallon it will go for a distance = 32*10= 320miles. Answer is A

PareshGmat · Answer

Answer = A. 320

Mileage at the speed of 60  = 40*\frac{80}{100} = 32  miles per gallon

In 10 gallons, distance travelled = 32*10 = 320

Konstantin1983 · Answer

40 miles=1 gallon at speed 45 miles/hour
40(1-0.2)=1 gallon ==> 32 miles=1 gallon at speed 60 miles/hour
Hence with 10 gallons at a speed 60 miles/hour car can travel 32*10=320 miles. Answer A

Bunuel · Answer

OFFICIAL SOLUTION:

Car Z travels 100% – 20%, or 80% of 40 miles per gallon of gasoline when traveling at 60 miles per hour. So the number of miles traveled per gallon of gasoline at 60 miles per hour is:
0.80 × 40 = 32 miles per gallon.

By multiplying the number of miles per gallon by 10 gallons, we can determine the distance that car Z travels on 10 gallons of gasoline:
32 × 10 = 320 miles.

The correct answer is choice (B).

gvvsnraju@1 · Answer

@60mph, Car's mileage is 32 miles/1 gallon.

1 gallon = 32 miles

10 Gallons = 320 miles

TheNightKing · Answer

Speed = 45. Mileage= 40
Speed =60. Mileage = 0.8*40=32

Distance at 60mph = 10 * 32 = 320

Answer A

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Car Z travels 40 miles per gallon of gasoline when driven at a constan

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