A man is thrice as old as his son. Five years ago ago the man was four times as old as his son. Find their present ages.
now:
son's age --- x
man's age --- 3x
5 years ago:
son's age = x-5
man's age = 3x-5
3x-5 = 4(x-5)
solve and the mystery will be unravelled.
To solve this problem, we can start by assigning variables to the ages of the man and his son. Let's say the son's age is "x" years.
According to the given information, the man is thrice as old as his son, which can be expressed as:
Man's age = 3 * Son's age
Man's age = 3x
Five years ago, the man was four times as old as his son, so we can write an equation based on this:
Man's age 5 years ago = 4 * Son's age 5 years ago
(Man's age - 5) = 4 * (Son's age - 5)
(3x - 5) = 4 * (x - 5)
Now, we can solve this equation to find the value of "x" (son's age):
3x - 5 = 4x - 20
x = 20 - 5
x = 15
Therefore, the son's present age is 15 years.
To find the man's age, we substitute the value of "x" back into the equation:
Man's age = 3x
Man's age = 3 * 15
Man's age = 45
So, the man's present age is 45 years, and the son's present age is 15 years.