A class had 9 students. In one test, the class average was 61. One student's paper was scored incorrectly, and the resulting score was raised 18 points. What is the corrected class average?
Correct Answer Choice 2. 63
Step by step solution
- Number of students in the class = 9
- Average marks as computed initially = 61
- Total marks = Average marks * number of students.
Hence, total marks of all 9 students computed with the initial average = 9 * 61 = 549
- Score for one of the student was raised by 18. This will contribute to the total score of the class increasing by 18 marks.
Therefore, new total marks for the class of 9 students = 549 + 18 = 567
- The new average = = = 63
The correct answer is Choice 2.
The total increases by 18 after the correction is made.
The effect of the increase of 18 in the total will be distributed equally among the 9 numbers when we compute the new average.
So, the effective increase in average will be = 2
Hence, the new average will be 2 more than the initial average. i.e., 2 + 61 = 63.
More Questions on Average & Statistics
- Average salary of new manager
- Wage of a worker on 8th day given average
- Average of 2 quantities
- Average Temperature for 5 days
- Average age of new students
- Average age of remaining students
- Average score of 3 classes
- Average weight of teacher
- Average of remaining quantities
- Average age of youngest member
- Difference between two digits
- Total cost of mangoes and apples
- Average age of girls & boys in a class
- XAT 2012 : Mean, Median, Mode
- TANCET 2013 : Change in average marks
XAT TANCET Practice Questions - Listed Topic wise
- Number Theory
- Permutation Combination
- Coordinate Geometry
- Data Sufficiency
- Profit Loss
- Ratio Proportion
- Mixtures & Alligation
- Speed Distance & Time
- Pipes, Cisterns & Work, Time
- Simple & Compound Interest
- Averages & Statistics
- Progressions : AP, GP & HP
- Set Theory
- Clocks Calendars
- Linear & Quadratic Equations
- English Grammar
- General Awareness