The average age of 9 men increases by 4 years when two of them, aged 28 years and 36 years, are replaced by two new men. What is the average age of the two new men?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 50 years
When the average of 9 men rises by 4 years, the total rises by \(9\times4\). The two new men bring in the ages of the two who left plus this extra.
Rise in the total \(=9\times4=36\) years
Ages of the two who left \(=28+36=64\) years
Total of the two new men \(=64+36=100\) years
Their average \(=100\div2=50\) years