Average age of 4 daughters of a family is 12 years. The average age of daughters and their parents is 26 years. If the mother is 4 years older than the father, then what is the age (in years) of the father?

Average age of 4 daughters of a family = 12 years

=> Sum of daughter's age = $$12\times4=48$$ years

Average age of daughters and their parents = 26 years

=> Sum of ages of 4 daughters and 2 parents = $$26\times6=156$$ years

=> Sum of parents age = $$156-48=108$$ years ------------(i)

Let father's age = $$x$$ years, => Mother's age = $$(x+4)$$ years

Substituting in equation (i),

=> $$x+x+4=108$$

=> $$2x=108-4=104$$

=> $$x=\frac{104}{2}=52$$ years

=> Ans - (B)