Question

the age of father is equal to the sum of the ages of its 5 children after 15 years sum of the ages of the children will be twice the age of the father find the age of the father

Answer 1

let fater age 5x then each children age will be x  
after 15 years


father age=5x+15
son age  =x+15
according to question 5x+15/x+15=1/2
                                 10x+30=x+15
                                 9x=45
                                    x=5
 father age 5x=5*5=25

Answer 2

AGE OF FATHER IS 45

x=a+b+c+d+e  (initially) --(1)
2(x+15)=a+15+b+15+c+15+d+15+e+15 (after 15 years)
2x+30=a+b+c+d+e+75
2x+30= x+75 (for equation 1)
x=45