RRB JE Mechanical Question Paper 2014 (Set-1) with Answer Key

Increase in sum of age during 3 years = 3 x 5 years
= 15 years
So , the difference between ages of old and new member is 15 years

x = 4y
So
4y×y=2500
4y^2=2500
y^2=(2500/4)=625
y=(square root of 625)=25
Thus x is (25×4)=100
Hence
x + y = (100 + 25) = 125

Let C's age be x years. Then, B's age = 2x years. A's age = (2x + 2) years.
∴ (2x + 2) + 2x + x = 27
⇒ 5x = 25
⇒ x = 5.
Hence, B's age = 2x = 10 years.