Question

A train covers 200 km in 4hrs 20 min. if the speed is increased by 18 km/hr, the time taken to cover the same distance...please explain in steps
1) 80 mts
2) 2hrs 10 min
3) 3hrs 10 min
4) 4 hrs 25 min... please explain in steps urgent please
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Answer 1

Answer:

3)3 hours 10 min

Step-by-step explanation:

Given that distance(d) = 200km, time(t) = 4hrs 20min

First convert time into hours

t = 4 + 20/60 = 4 + 1/3 = (12 + 1)/3 = 13/3 hrs

Then calculate Speed(v1)

v1 = d/t = 200/(13/3) = (200*3)/13 = (600/13) km/hr

Now speed increased by 18km/hr

v2 = v1 + 18 = (600/13) + 18 = (600 + 234)/13 = (834/13) km/hr

So Time(t2) = d/v2

t2 = 200 / (834/13) = (200 * 13) / 834 = 2600/834 hr

t2 = 3.117 hrs or 3hr 7min 1 sec

Ans: Time = 3.117 hrs or 3hr 7min 1 sec

you can write it as 3 hours 10 min