If the sum of the ages of a father and his son in years is 65 and twice the difference of their ages in years is 50, then the age of the father is:
Let father's age =x, son's age =y
As per question,
x+y=65⇒y=65−x .....(1)
2(x−y)=50⇒2x−2y=50 .......(2)
⇒2x−2(65−x)=50 [ substituting value of y from equation (1) in equation (2) ]
⇒2x−130+2x=50
⇒x=45
So father's age =45 years