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1. A car goes 15 miles on a gallon of octane when it is driven at 50 miles per hour. When the car is driven at 60 miles per hour, it only goes 80% as far. How many gallons of octane is needed to travel 200 miles if half the distance is traveled at 50 miles per hour and the rest at 60 miles per hour?
- A. 13.33
- B. 13.33
- C. 13.33
- D. 13.33
Answer: Option D
Explanation:
A car goes 15 km with a gallon of octane at 50 km/hr.
Again,
If travels with 60 km/hr, it goes 80% far as that of before. i.e.
D = 80%×15 = 12 km.
Now,
According to question, if 100 km is travelled in 50 km/hr and another 100 km in 60 km/hr then,
In 50 km/hr: 1 gallon = 15 km
In 60 km/hr: 1 gallon = 12 km
Hence,
Total required gallons of octane is;
100/15 + 100/12
= 15 gallons.
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