Five years ago, the average age of four men was 48 yr. Now, a new man joins and the average age increases by 2 yr. What is the age of the new man?

Sum of the ages of 4 men five years ago
= 48 x 4
=192 yr
And sum of present ages of the four men
= 192 + 5 x 4
= 212 yr
Now ( 212 + Age of the new man ) / 5 = 50
∴ Age of the new man = 50 x 5 - 212
= 38 yr.