Correct Answer - Option 4 : 12 km/h
Calculation:
⇒ Let’s suppose that the time taken by Satyajit Ray at 10 km/h to cover the distance by 1 pm = t h
⇒ Now at speed of 15 km/h the time taken = (t - 2) h
⇒ Now the distance covered is the same so we can say that
⇒ 10(t) = 15(t - 2)
⇒ t = 6
⇒ Therefore, the distance covered will be = 10 x 6 = 60
⇒ Therefore, the speed at which Satyajit Ray has to travel to reach the place at noon = 60/(t - 1) = 60/5 = 12 km/h