Jackson travels a distance of 100km in 5 hrs. How much faster in kilometer per hr, on an average, mu

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21 Dec 2020 Speed

Jackson travels a distance of 100km in 5 hrs. How much faster in kilometer per hr, on an average, must he travel to make a journey in 5/3 hr less time?

OPtion

1) 5 km/hr
2) 10km/hr
3) 6 km/hr
4) 8 km/hr
5) 9 km/hr
6) 8.5 km/hr
7) 6 km/hr
8) 7 km/hr
9) 6.5 km/hr
10) None of the above

Solution

Time required = (5 hrs – 5/3 hrs)
=(5 hrs – 100 mints) = (5 hrs – 1hr 40 mints)
= 3 hrs 20 mints = 3 1/3 hrs
Required speed = (100*3/10) km/hr =30 km/hr
Original speed = (100/5)km/hr = 20 km/hr
Difference speed = required speed – original speed
=(30-20) =10km/hr

Correct Option: 2 Best Solution (2)