Ravi starts for his school from his house on his cycle at 8:20 a.m. If he runs his cycle at a speed of 10 km/h, he reaches his school 8 minutes late, and if he drives the cycle at a speed of 16 km/h, he reaches his school 10 minutes early. The school starts at:
Answer & explanation
Correct answer: option 3
We know that ,
Speed = \(\frac{Distance}{Time}\)
Speed ∝ \(\frac{1}{Time}\)
Ratio of speed , S1 : S2
10 : 16
Time 16 : 10
8 : 5
According to question,
( 8 - 5)R = 18 minutes
3R = 18 minutes
1R = 6 minutes
Time taken by speed 10 km/h = 8 x 6 = 48 minutes
If he runs his cycle at a speed of 10 km/h, he reaches his school 8 minutes late
So, Actual time = 48 - 8 = 40 minutes
So, College starts at = 8:20 am + 40 minutes
= 9 am