Correct Answer - Option 4 : 360 km
GIVEN:
A man completes a journey in 15 hours. He travels first half of the journey at the rate of 20 km/hr and second half at the rate of 30 km/hr.
FORMULA USED:
Speed = Distance/Time
CALCULATION:
Suppose total distance = A km
So,
(A/2)/20 + (A/2)/30 = 15
⇒ A/40 + A/60 = 15
⇒ 5A/120 = 15
⇒ A = 360
Hence, total distance = 360 km