George walks 36 kms partly at a speed of 4kms per hour and partly at 3 kms per…
2025
George walks 36 kms partly at a speed of 4kms per hour and partly at 3 kms per hour. If he had walked at a speed of 3kms per hour when he had walked at 4 and 4 kms per hour when he had walked at 3he would have walked only 34 kms. The time (in hours) spent by George walking was:
- A.
8
- B.
12
- C.
5
- D.
10
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Correct answer: D
Let x be the number of hours George walked at 4 km/h and let y be the number of hours he walked at 3 km/h.
Distance covered gives the equation 4x + 3y = 36
If the speeds were swapped for the same time periods, the distance would be 3x + 4y = 34
Subtract the second equation from the first: x - y = 2 so x = y + 2.
Substitute into 4x + 3y = 36: 4(y+2) + 3y = 36 ⇒ 7y = 28 ⇒ y = 4.
Then x = 6, so total time x + y = 10 hours.
Answer: 10 hours.