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:

Let the distance between Ravi's house and his school = $$d$$

Time taken by him when he runs his cycle at a speed of 10km/h = $$\frac{d}{10}$$

Time taken by him when he drives his cycle at a speed of 16km/h = $$\frac{d}{16}$$

According to the problem,

$$\frac{d}{10}-\frac{d}{16}=\frac{18}{60}$$ hours

$$=$$>  $$\frac{8d-5d}{80}=\frac{18}{60}$$

$$=$$>  $$\frac{3d}{80}=\frac{18}{60}$$

$$=$$>  $$d=8$$ km

Time taken by him when he runs his cycle at a speed of 10km/h = $$\frac{8}{10}$$ hour = $$\frac{8}{10}\times60$$ minutes = 48 minutes

The time at which school starts = 8:20 a.m+ 48 minutes - 8 minutes = 8:20 + 40 minutes = 9:00 a.m

Hence, the correct answer is Option D