Question

Three years ago the sum of the ages of 4

brothers was x. What will be the arithmetic mean
of their ages 5 years from now?
A) X/4 +8
B) X/4 + 5
C) X + 5
D) X/2 - 1
E) X+20/5

Answer 1

Explanation:

Let the ages of the 4 brothers three years ago be a, b, c, and d. The sum of their ages three years ago is x:

x = a + b + c + d

In five years, their ages will be a + 8, b + 8, c + 8, and d + 8. The arithmetic mean of their ages in five years will be:

[(a + 8) + (b + 8) + (c + 8) + (d + 8)] / 4

Simplifying:

(a + b + c + d + 32) / 4

We know that a + b + c + d = x (from the given information), so substituting:

(x + 32) / 4

Therefore, the answer is A) X/4 +8.