Question

Mrs. Anna has 4 Children = Alex,Brad,Christine, and Dennis. Alex is not the youngest, but he is younger than Dennis. If Brad's age is the same as the mean of the ages of Alex and Dennis, then the oldest one is .........​

Answer 1

Let's say Alex, Brad, Christine and Dennis in terms of A, B, C and D.

From the question term, Alex is younger than Dennis. So D > A.

Then, Brad's age is the same as the mean of the Alex and Denis. Which have possibilitiy that Brad's ages is between Alex and Dennis (Arithmatic mean theory) : D > B > A.

The conclusion is : Chirstine is the youngest one. And Dennis is the oldest.