SOLUTION: a man drives for 30 minutes at a speed of 25 m/s then stops for 10 minutes and finally drives for 20 minutes at 36 m/s. Calculate (a)the total distance and (b) the average speed.

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: a man drives for 30 minutes at a speed of 25 m/s then stops for 10 minutes and finally drives for 20 minutes at 36 m/s. Calculate (a)the total distance and (b) the average speed.      Log On

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Question 629120: a man drives for 30 minutes at a speed of 25 m/s then stops for 10 minutes and finally drives for 20 minutes at 36 m/s. Calculate (a)the total distance and (b) the average speed.
Answer by 303795(602) About Me  (Show Source):
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He firstly travels for 30 mins at 25 m/s
i.e. he travels for 30 x 60 = 1800 seconds
The distance he travels will be 1800 x 25 =45000 m (45 km)
His second set of travelling is for 20 minutes at 36 m/s
i.e. he travels for 20 x 60 = 1200 seconds
The distance he travels will be 1200 x 36 = 43200 m (43.2 km)
The total distance he travels will be 45000 + 43200 = 88200 m.
This means his average speed as the overall journey took one hour is 88.2 km/h or 88200/3600 = 24.5 m/s.