Shyam drives his car 30 km at a speed of 45 km/h and, for the next 1 h 20 m, he drives it at a speed of 51 km/h. Find his average speed (in km/h) for the entire journey.
Answer & explanation
Correct answer: option 1
Shyam drives is 30 km at a speed of 45 km/h
And 45 km/h in 60 min
So , Shyam can go 3 km in 4 min
He go 30 km in 40 min
for the next 1 h 20 m, he drives it at a speed of 51 km/h
1 h 20 min = \(\frac{4}{3}\) hours
Distance traveled in \(\frac{4}{3}\) hours with speed 51 km/h ,
= 51 × \(\frac{4}{3}\) hours = 68 km
Total distance = 30 + 68 = 98 km
Total Time = 40 min + 1hr 20 min = 2 hours
Average speed = \(\frac{98}{2}\) = 49 km