Father/Son Age Riddle

Let the son's age be x. Son's age 5 years ago = x-5 Son's age in the future = x+5 Father's age in the past = 7(x-5) Father's age in the future = 3(x+5) Father's present age with respect to past age and future age 7(x-5)+5=3(x+5)-5 Expand and simplify 7x-35+5=3x+15-5; 7x-3x=35-5+15-5; 4x=40; x=10

Sons age 5 years ago=x father's age = 7x their present age = x+5 and 7x+5 resp Sons age 5 years hence = x+10(since x is sons age 5 years ago from present age and we are talking of his age 5 years hence from his present age so 5+5=10) fathers age 5 years hence =3(x+10) hence the fathers present age will be 3(x+10)-5 also fathers present age =7x+5 therefore 7x+5=3(x+10)-5 7x+5=3x+30-5 7x-3x=25-5 4x=20 x=5 sons age 5 years ago=5 years fathers age =5 7=35 years present age of the son=(5+5)=10 years fathers age=35+5=40 years sons age 5 years hence= 5+10=15 years fathers age =3 (5+10)=45 years

suppose, 5 years ago the age of son is x so the present age of son is (x+5) the equation is , 7x+5+5= 3(x+5+5) or,7x+10=3(x+10) or,7x+10=3x+30 or,7x-3x=30-10 or,4x=20 or, x=5 So, the present ageof son is (5+5)=10.