A car covers first half of its journey at the rate of 15km/h and secon...
Let total distance be x
(x/2)/15+(x/2)/12=9
=>x/15+x/12=18
=>x=(60×18)/9=120kmph
A car covers first half of its journey at the rate of 15km/h and secon...
Given information:
- Car covers first half of the journey at 15 km/h
- Car covers second half of the journey at 12 km/h
- Total time taken to complete the journey is 9 hours
To find: Length of journey
Approach:
Let's assume that the total distance to be covered is 'd' km.
We know that distance = speed x time
Using this formula, we can find the time taken to cover the first half and second half of the journey separately.
- Time taken to cover the first half = (d/2) / 15 = d/30 hours
- Time taken to cover the second half = (d/2) / 12 = d/24 hours
- Total time taken = d/30 + d/24 = 9 hours
We can solve this equation to find the value of 'd'.
LCM of 30 and 24 is 120, so we can multiply both sides by 120 to eliminate the denominators.
4d + 5d = 1080
9d = 1080
d = 120 km
Therefore, the length of the journey is 120 km. Hence, option C is the correct answer.