Multiple choice

Shalini travels at a speed of 5 km/h for office from home and reaches 5 minutes late. In the return trip, she travels at 6 km/h to reach her home and reaches 7 minutes earlier. What is the distance between her office and home?

  1. 6 km

  2. 9 km

  3. 4 km

  4. 3 km

  5. 2 km
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let distance be D. Time taken at 5 km/h is D/5. Time taken at 6 km/h is D/6. Given (D/5) - (D/6) = (5+7)/60 = 12/60 = 1/5. Solving D/30 = 1/5 gives D = 6 km.

AI explanation

Let the exact time to reach the office be t minutes. Using the formula time equals distance divided by speed, we write (D divided by 5) equals (t plus 5) divided by 60 and (D divided by 6) equals (t minus 7) divided by 60. Converting these to a common ratio, D multiplied by 12 equals t plus 5 and D multiplied by 10 equals t minus 7. Subtracting the second equation from the first gives 2D equals 12, so D is 6. The distance is 6 km.

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