The average age of four boys A, B, C and D is 5 years, and the average age of A, B, D and E is 6 years. If C is 8 years old, what is the age of E (in years)?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 12
The two groups share A, B and D, so the difference of the two totals is the difference between E and C.
A \(+\) B \(+\) C \(+\) D \(=4\times5=20\)
A \(+\) B \(+\) D \(+\) E \(=4\times6=24\)
E \(-\) C \(=24-20=4\)
E \(=8+4=12\) years