Question

a father is twice as old as his son 20 years ago the age of the father was 12 times the age of the son the present age of the father is?

Answer 1

let son be x years
father = 2x
..
20 years ago
son = x-20
father = 2x-20
..
2x-20=12*(x-20)
2x-20 = 12x -240
add 20 to both sides
2x = 12x-240+20
2x=12x-220
add -12x to both sides
2x-12x= 12x-12x-220
-12x+2x= -240+20
-10x= -220
divide by -10
x= -220/-10
x=22 son's age
Father's age = 2*22 = 44 years
I hope it will help u....

Answer 2

let father age be y
sons age be x
2x = y. 1eq
20years ago
12(x - 20) = (y-20)
12x - 240 = y -20
12x - y= 220 2 eq
substituting 1 in 2
12x - 2x = 220
10x = 220
sons age = 22
father's age = 44