79
81
84
16
The mean of 100 items was found to be 40. If at the time of calculation two items were wrongly taken as 36 and 32 instead of 54 and 34, the correct mean is
The mean of 100 observations was calculated as 40. It was found later on that one of the observations was misread as 83 instead of 53. The correct mean is :
The mean of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is
The mean of ten observations is 23. If two observations 4 and 7 are substituted by 3 and 8, then the new value of mean will be
The mean of the first 7 prime numbers is:
The mean proportional between 0.32 and 0.02 is
The mean weight of 100 students in a class is 46 kg. The mean weight of boys is 50 and of girls is 40 kg. Therefore, the number of boys is:
The mean weight of 150 students in a class is 60 kg. The mean weight of boys is 70 kg and that of girls is 55 kg. What is the number of boys in the class?
The milk and water in a mixture are in the ratio 7 : 5. When 15 liters of water are added to it, the ratio of milk and water in the new mixture becomes 7 : 8. The total quantity of water in the new mixture is:
The minute hand of a clock overtakes the hour hand at intervals of 58 min of the correct time. How much does a clock gain or lose in a day?
