Question
Two cars start from a place with a speed of 35 km/hr at
an interval of 10 minutes. What is the speed of a man coming from the opposite direction towards the place if he meets the cars at an interval of 7 minutes?Solution
Distance covered in 10 minutes at 35 km/hr = 35 x (10/60) Distance covered in 7 minutes at (35 + x) km/hr = (7/60) x (35 + x) Now, Distance covered in 10 minutes at 35 km/hr = Distance covered in 7 minutes at (35 + x) km/hr ⇒ 35 x (10/60) = (7/60) x (35 + x) ⇒ 35 x 10 = 245 + 7x ⇒ 350 = 245 + 7x ⇒ 7x = 350 - 245 = 105 ⇒ x = 15 km/hr
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