The GMAT Math practice question given below is a sequences and series question based on Arithmetic Mean
The average of 5 consecutive integers starting with m as the first integer is n. What is the average of 9 consecutive integers that start with m+2?
- m + 4
- n + 6
- n + 3
- m + 5
- n + 4
The correct choice is (E) and the correct answer is
n + 4.
The fastest way to solve problems of this kind is to take numerical examples.
The average of 5 consecutive integers from 1 to 5 is 3. Therefore, the value of m is 1 and the value of n is 3.
Now, the average of 9 consecutive integers starting from m + 2 will be average of integers from 3 to 11.
The average of numbers from 3 to 11 is 7.
Now look at the answer choices. Only choice (E) satisfies this condition.