nafishasan wrote:If the average of 5 positive integers is 40 and the difference between the largest and the smallest of these 5 numbers is 10, what is the maximum value possible for the largest of these 5 integers?
A. 52
B. 50
C. 49
D. 48
E. 44
Sum = number*average = 5*40 = 200.
We plug in the answers, which represent the maximum possible value of the largest integer.
To MAXIMIZE the largest integer, we must MINIMIZE the other 4 integers.
Thus, the other 4 integers must ALL be equal to the smallest integer.
Thus, when the correct answer choice is subtracted from 200, the result must be a multiple of 4, so that each of the other 4 values becomes an integer.
Eliminate B (200-50=150, which is not a multiple of 4) and C (100-49=151, which is not a multiple of 4).
Answer choice A: 52
Each of the other 4 integers = (200-52)/4 = 37.
Largest - smallest = 52-37 = 15.
The difference is not 10.
Eliminate A.
Answer choice D: 48
Each of the other 4 integers = (200-48)/4 = 38.
Largest - smallest = 48-38 = 10.
Success!
The correct answer is
D.
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