the sum of ages of father ans his son is 60 years. after 14 years,fathers age will be three times the age of the son. find their present ages
Answers
- The sum of ages of father ans his son is 60 years
- After 14 years , Father's age will be three times the age of the Son
- Present age of Father
- Present age of Son
Let the present age of Father be x years.
Let the present age of Son be y years.
- The sum of ages of father ans his son is 60 years
Representing the given condition mathematically.
=> Father's age + Son's age = 60
=> x + y = 60 ----> 1
- After 14 years , Father's age will be three times the age of the Son.
Ages after 14 years :-
Father's age = x + 14 years
Son's age = y + 14 years
Representing the condition mathematically.
=> x + 14 = 3 ( y + 14)
=> x + 14 = 3y + 42
=> x - 3y = 42 - 14
=> x - 3y = 28 ----> 2
Solve equations 2 and 1 simultaneously by elimination method.
Subtract equation 2 from equation 1,
....+ x + y = 60 ----> 1
- ( + x - 3y = 28 ) -----> 2
________________
4y = 32
y =
y = 8
Substitute the value of y in equation 2,
=> x - 3y = 28
=> x - 3 ( 8 ) = 28
=> x - 24 = 28
=> x = 28 + 24
=> x = 52
For first case :-
- The sum of ages of father ans his son is 60 years
Present age of Father = x = 52 years
Present age of Son = y = 8 Years
=> Father's age + Son's age = 60
=> x + y = 60
=> 52 + 8 = 60
=> 60 = 60
LHS = RHS.
For second case :-
- After 14 years , Father's age will be three times the age of the Son
Ages after 14 years :-
Father = x + 14 = 52 + 14 = 66 years
Son = y + 14 = 8 + 14 = 22 years
=> x + 14 = 3 ( y + 14)
=> 66 = 3 ( 22)
=> 66 = 66
LHS = RHS.
Hence verified.
This question can be solved by both Linear equation in one variable as well as Linear equation in two variables.
I am solving with Linear equation at first.
According to question,
1. Sum of Son's and Father's age is 60.
2. After 14 years, father's age will be 3 times of Son's age.
Let the age of Son = x
And Father's age = 60-x
After 14 years,
Son's age = X+14
Father's age = 74-x
3(X+14) = 74-x
3x + 42 = 74-x
4x = 32
x = 8 years.
Hence,
Son's age = X = 8 years
Father's age = 60-x = 52 years.
Now, solving by Linear equation in two variables.
Son's age = x years
Father's age = y years
x + y = 60 -------(1)
Now, After 14 years,
3(x+14) = y+14
3x - y = 42-14
3x-y = 28 ------(2)
From (1) & (2)
x+y = 60
3x-y = 28
______________
4x = 32
x = 32/4
x = 8 years.
Putting the value of x in eq (1)
x + y = 60
8 + y = 60
y = 52 years.
x = 8 years. Answer....