Part C - Elementary Mathematics
Sanjay and Tannu working separately can do a piece of work in 6 and 20 days, respectively. If they work for an alternate day, Tannu beginning, in how many days will the work be completed?
In an English exam of 50 marks of a class, 20 students had an average score of 40 marks, 25 students had an average score of 34 marks and 15 students had an average score of 26 marks. What is the weighted average score of the entire class?
A bus goes from city P to Q in 45 minutes, covering a distance of 60 km, and comes back to city P with a speed of 40 km/hr. The average speed of the bus in the journey is _____ km/hr (correct to two decimal places).
Three-fifth of a journey is covered at a speed of 84 km/hr, and the remaining distance is covered at the rate of 56 km/hr. The average speed for the whole journey (in km/hr) is: