The average of seven numbers is 18. If one of the numbers is 17 and if it is replaced by 31, then the average becomes :

Distance between two stations A and B is 778km. A train covers the journey from A to B at 84 km per hour and returns bac…

The average of runs scored by a cricketer in his 99 innings is 99. How many runs will he have to score to his 100th inni…

The mean weight of 34 students of a school is 42 kg. If the weight of the teacher be included, the mean rises by 400 gra…

The average weight of three boys A, B and C is $$54\frac{1}{3}$$ kg, while the average weight of B, D and E is 53 kg. Wh…

When a student weighing 45 kgs left a class, the average weight of the remaining 59 students increased by 200g. What is …

The average age of an adult class is 40 years. 12 new students with an average age of 32 years join the class, thereby d…

A student obtained the following marks in percentage in his semester examination English 50, Maths 65, Statistics 70, Ec…