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Question
Distance between Bholu’s and Golu’s house is 9 km. Bholu has to attend Golu’s birthday party at 7 o’clock. He started from his home at 6 o’clock on his bicycle and covered a distance of 6 km in 40 minutes. At that point, he met Chintu and he spoke to him for 5 minutes and reached Golu’s birthday party at 7 o’clock. With what speed did he cover the second part of the journey? Calculate his average speed for the entire journey.
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Solution
Distance between Bholu’s and Golu’s house = 9 km
Distance covered by Bholu in first part of the journey = 6 km
Time taken to cover 6 km = 40 min
Distance covered by Bholu in second part of the journey = 9 − 6 = 3 km
Time taken to cover 3 km = 60 – (40 + 5) = 15 min
Speed of Bholu while covering second part of the journey
= `(3 "km")/((15/60)"h")`
= 12 km/h
Average speed of Bholu for the entire journey
= `("Total distance")/("Time taken")`
= `(9 "km")/(60 "min")`
= 9 km/h
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