# Moderate Time, Speed & Distance Solved QuestionAptitude Discussion

 Q. Starting from my office, I reach the house 20 min late if I walk at 3kmph. Instead, if I walk at 4 kmph, I reach the house 15 min early. How far is my house from my office?
 ✖ A. 4 km ✖ B. 5 km ✔ C. 7 km ✖ D. 6 km

Solution:
Option(C) is correct

Let the distance between the office and the house be 1 km

Time required at 3 kmph

$=\dfrac{1}{3} =20$min

Time required at 4 kmph

$=\dfrac{1}{4} =15$min

Difference = $20−15=5$ min.

Actual difference in timings = $20+15=35$ min

If difference is 5 min, distance is 1 km

$⇒$ If difference is 35 min, distance is 7 km