five years ago a man was seven times as old his son five years hence the father will be three times as old as his son find there present age
Answers
Answer:
Father's present age is 40 years and son's present age is 10 years.
Step-by-step explanation:
Given :-
- 5 years ago, a man was 7 times as old as his son.
- 5 years hence, the father will be 3 times as old as his son.
To find :-
- Their present ages.
Solution :-
Let the present age of father be x years and the present age of son be y years.
5 years ago,
- Father's age = (x-5) years
- Son's age = (y-5) years
According to the question,
x-5 = 7(y-5)
→ x-5 = 7y -35
→ x = 7y-35+5
→ x = 7y-30..................(i)
After 5 years,
- Father's age = (x+5) years
- Son's age = (y+5) years
According to the question,
x+5 = 3(y+5)
→ x+5 = 3y+15
- Put x = 7y-30 from eq (i).
→ 7y-30+5 = 3y+15
→ 7y - 3y = 15+30-5
→ 4y = 40
→ y = 10
Now put y = 10 in eq(i) for getting the value of x.
x = 7y-30
→ x = 7×10-30
→ x = 40
Therefore,
★ Present age of father is 40 years.
★ Present age of son is 10 years.
Answer:
sons age: 10
father's age: 40
Step-by-step explanation:
let the present age of man be x.
let the present age of his son be y.
five years ago......
father's age= x-5
sons age=y-5
x-5=7(y-5)
x-5=7y-35
x=7y-35+5
x=7y-30(equation 1)
five years hence....
father's age= x+5
sons age= y+5
x+5=3(y+5)
x+5=3y+15(equation 2)
substituting value of x from equation 1 into equation 2
(7y-30)+5=3y+15
7y-25=3y+15
7y-3y=15+25
4y=40
y=40/4
y=10
this implies....
sons age=y= 10 years
father's age= x=7y-30
=70-30
father's age= 40 years....
hope it helps you:))