Carcass wrote:
The average of 7 distinct integers is 12, and the least of these integers is -15. What is the maximum possible value of the largest integer in the set?
A. 84
B. 158
C. 159
D. 160
E. 161
The average of 7 distinct integers is 12, and the least of these integers is -15If we let a, b,... to g represent the seven integers in
ascending order, we can write: \(\frac{a+b+c+d+e+f+g}{7}=12\)
Multiply both sides of the equation by \(7\) to get: \(a+b+c+d+e+f+g = 84\)
Since the smallest number is -15, we can write: \((-15)+b+c+d+e+f+g = 84\)
What is the maximum possible value of the largest integer in the set?In order to maximize the largest integer (aka g), we must MINIMIZE the other values in the sum.
Since each integer must be
distinct, the second smallest integer must be -14, and then -13, and so on.
We get: \((-15)+(-14)+(-13)+(-12)+(-11)+(-10)+g = 84\)
Simplify: \((-75)+g = 84\)
Add \(75\) to both sides: \(g = 159\)
Answer: C