Ramesh drives from his home at a speed of 40 km/h and reaches his college 25 minutes late. The next day he increases his speed by 10 km/h, yet he is late by 10 minutes. How far is his college from his home?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 50 km.
Formula used:
Distance = Speed/time ---- (1)
Calculations:
Let the distance be D and t be the time, according to the question using equation (1)
⇒ D/40 = t + 25 ---- (2)
⇒ D/50 = t + 10 ---- (3)
Equating, equation (3) - equation (2), we get
⇒ D/40 - D/50 = 15
⇒ (5D - 4D)/200 = 15/60
⇒ D/200 = 1/4
⇒ D = 50 km