If the arithmetic mean of seventy five numbers is calculated, it is 35. If each number is increased by 5, then mean of new number is___________?
Correct answer: B. 40
- A. 30
- B. 40
- C. 70
- D. 90
Explanation
Adding 5 to every observation increases the arithmetic mean by exactly 5, because the same constant is added to every value. Therefore, the new mean is 35 + 5 = 40. A student may choose 30 by subtracting 5 instead of adding it.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Averages
An average represents the total of a set of values divided by the number of values, and a weighted average gives different importance to different groups. Problems involve missing values, combined averages, replacement of observations, and changes in the average, so the total and count must be tracked separately.
Practise Arithmetic
1,060 free Arithmetic MCQs from Mathematics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Mathematics questions like this
Mathematics is on 76 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Averages questions
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___________?
A pupil's marks were wrongly entered as 83 instead of 63. Due to the average marks for the class got increased by half. The number of pupils in the class is___________?
The average age of 15 students of a class is 15 years. Out of these, the average age of 5 students is 14 years and that of the other 9 students is 16 years. The age of the 15th student is____________?
In the first 10 overs of a cricket game, the run rate was only 3.2. What should be the rate in the remaining 40 overs to reach the target of 282 runs?
The average of runs of a cricket player of 10 innings was 32. How many runs must he make in his next innings so as to increase his average of runs by 4?
The average of 35 students in a class is 16 years. The average age of 21 students is 14. What is the average age of remaining 14 students?