Two cars run to a place at the speeds of 45 km/h and 55 km/h, respectively. If the second car takes 40 minutes less than the first for the journey, then what is the length of the journey (in km)?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 165
Let the length of the journey be x km.
Speed of the the two cars is 45 km/h and 55 km/h respectively.
The second car takes 40 minutes less than the first car i.e. 2/3 hours less than the first car.
Time = Distance/Speed
Time taken by the first car = x/45
Time taken by the second car = x/55
According to the question -
⇒ x/45 - x/55 = 2/3
⇒ (11x - 9x)/495 = 2/3
⇒ x = (495 × 2)/(3 × 2)
⇒ x = 165 km