when the son will be as old as his father today,the sum of their ages ...
Problem: When the son will be as old as his father today, the sum of their ages will be 126 years. When the father was as old as his son is today, the sum of their ages was 38 years. Find their present ages.
Solution:
Let the present age of the son be x and the present age of the father be y.
According to the first condition, when the son will be as old as his father today, the sum of their ages will be 126 years.
So, x + y + y = 126
=> x + 2y = 126 ----(1)
According to the second condition, when the father was as old as his son is today, the sum of their ages was 38 years.
So, x + x + y = 38
=> 2x + y = 38 ----(2)
Now, we have two equations (1) and (2) in two variables (x and y). We can solve these equations to find the values of x and y.
Multiplying equation (2) by 2 and subtracting it from equation (1), we get:
x = 50
Substituting the value of x in equation (2), we get:
y = 19
Therefore, the present age of the son is 50 years and the present age of the father is 19 years.
Answer:
Present age of the son = 50 years
Present age of the father = 19 years.
when the son will be as old as his father today,the sum of their ages ...
Let son 's current age is x and father 's current age is y.
Where does the(y-x) term come from? Well, it says 'when the son will be as old as the father is today, which means that the son has to age a certain amount of years. How many years does he have to age? The difference between his current age and his father 's current age.
For example, if the son was 10 and the father was 40, it would take the son 30 years (or y-x = 40-10) to reach his current age. In the meantime, the father would age the same amount (y - x = 40 - 10 = 30 years).
[Father 's new age] + [Son 's new age] = 126
[y+(y-x)] + [(x + (y-x))] = 126
⇒ 2y - x + y = 126
∴ 3y - x = 126 -(1)
[Father 's previous age] + [Son 's previous age] = 38
⇒ [y - (y-x)] + [x - (y-x)] = 38
⇒ x + x - y + x = 38
⇒ 3x - y = 38
∴ y = 3x - 38 -(2)
Now sub equ(2) into equation 1
⇒ 3(3x-38) - x = 126
⇒ 9x - 114 - x = 126
⇒ 8x = 240
∴ x = 30
Now y = 3x - 38
⇒ y = 3(30) - 38
∴ y = 52
The son is 30 years old, and the father is 52 years old.
source:brainly.com
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