If the average of 31, x, 42, 39, 56, 78, 83 and 91 is 58.5, then what is the value of x?

 

Four numbers A, B, C and D are such that their overall average is 16. The average of A and B is 9.5. The average of C and D is

The average marks obtained by Raghav in 12 tests is 24. Zubeida has maintained an average of 23 so far but has taken only 9 of the tests. If each test is out of 30, at least how much Zubeida score in any one of the remaining three tests to still have a chance to match Raghav's performance?

A person purchased 10 shirts costing Rs 150 per shirt. Next day  he again purchased the shirts costing Rs 150 per shirt at a discount of Rs 30 per shirt and that day he spent a toal of Rs 1800. What is the average cost per shirt (in Rs)?

The average weight of 30 students in a class is 25 kgs. If the weight of the class teacher is added, the average weight increase by 2 kgs. The weight of the class teacher in kgs is

The average of 5 consecutive numbers is 50%, then difference between 'product of largest and smallest number' with 'product of fourth and second number' is

In a cricket match, the scores of the players are considered such that coefficient of variation of scores is 16 and mean is 25 then the variance is

After 10 innings the average score per innings of a batsman was 52. After 12 innings the average rose to 54. If the batsman had scored 16 more runs in the 12th innings than in the previous one, how many runs did he score in the 11th innings?

The mean of 12 observations is 15. One more observation is included and the new mean becomes 16. The 13th observation is