five years ago ram was twice as old as Shyam . fifteen years ago ram was four times as old as Shyam . find their present ages
Answers
- Five years ago ram was twice as old as Shyam
- Fifteen years ago ram was four times as old as Shyam
- Present age of Ram
- Present age of Shyam
Let the present age of Ram be x years.
Let the present age of Shyam be y years.
- Five years ago ram was twice as old as Shyam
Ages 5 years ago :-
Ram's age = x - 5 years
Shyam's age = y - 5 years
Representing mathematically,
=> x - 5 = 2 ( y - 5)
=> x - 5 = 2y - 10
=> x - 2y = - 10 + 5
=> x - 2y = - 5 -----> 1
- Fifteen years ago ram was four times as old as Shyam
Ages 15 years ago :-
Ram's age = x - 15 years
Shyam's age = y - 15 years
Representing second condition mathematically,
=> x - 15 = 4 ( y - 15)
=> x -15 = 4y - 60
=> x - 4y = - 60 + 15
=> x - 4y = - 60 ----> 2
Solve equations 1 and 2 simultaneously by elimination method.
Subtract equation 2 from 1,
....+ x - 2y = - 5 -----> 1
- ( + x - 4y = - 45 ) -----> 2
________________________
2y = 40
y =
y = 20
Substitute y = 20 in equation 1,
x - 2y = - 5 ----> 1
x - 2 ( 20 ) = - 5
x - 40 = - 5
x = - 5 + 40
x = 35
•°• Present age of Ram = x = 35 years
Present age of Shyam = y = 20 years.
SOLUTION:-
Given:
⚫5 years ago Ram was twice as old as Shyam.&
⚫15 years ago ram was four times as old as Shyam.
Therefore,
Let the age of Shyam= x years
Let the age of Ram = y years.
So, 5 years ago:
Age of Shyam= (x-5) years
Age of Ram = (y-5) years.
As the Ram was twice times older than Shyam 5 years ago:
=) y-5 = 2(x-5)
=) y-5 = 2x-10
=) y -2x= -10+5
=) y -2x= -5....................(1)
Now,
15 years ago;
Age of Ram= (y-15)years
Age of Shyam= (x-15) years
So,
15 years ago, age of Ram will four times the age of Shyam:
=) y-15 = 4(x-15)
=) y-15 = 4x - 60
=) y - 4x = -60+15
=) y -4x = -45...............(2)
Therefore,
Subtracting equation (1) from (2), we get;
=) -2x= -40
=) x= 40/2 [Minus Cancel]
=) x= 20
Therefore,
Putting the value of x in equation (1), we get:
=) y -2(20)= -5
=) y - 40= -5
=) y= -5 +40
=) y= 35
Thus,
Present age of Ram,(y) = 35 years.
Present age of Shyam,(x)= 20 years.