Correct Answer - Option 1 : 12 min
GIVEN:
Ram walks at a speed of 10 km/h. Today the day was very hot so walked at 2/5th of his average speed. He arrived at his school 18 minutes late.
FORMULA USED:
Time = Distance/Speed
CALCULATION:
Suppose the distance between his school and home = X km
Decreased speed = 10 × 2/5 = 4 kmph
According to the question:
X/4 - X/10 = 18/60 = 3/10
⇒ X = 2 km
So,
Usual time he takes to cover the distance between his school and home = 2/(10/60) = 12 min