when the son will be as old as his father today, the sum of their ages then will be 126. when the father was as old as his son today ,the sum of there ages then was 38. find the present age father and son
Answers
We shall represent the son's age 'today' by S and the father's age 'today' by F.
The first peace of information we have is that when the son's age(S+a few years) shall be equal to the father's present age(F), the sum of their ages shall be
126
.
we shall then note that S
+
x
=
F
where
x
represent a number of years.
We now say that in
x
years the father's age will be F
+
x
.
So the first information we have is : S
+
x
+
F
+
x
=
126
but S
+
x
=
F
→
x
=
F-S
⇒
3
F
−
S
=
126
......(1)
The second information is that when the father's age was equal to the son's present age(father = F - a few year = S), the sum of their ages was
38
.
we shall then note that F
−
y
=
S
where
y
represent a number of years.
This means that
y
years earlier the father's age was F
−
y
.
This information translated into math is : F
−
y
+
S
−
y
=
38
but F
−
y
=
S
→
y
=
F-S
⇒
3
S-F
=
38
......(2)
Step-by-step explanation:
Let present ages be s, f
Age of son after becoming as of as father =f
time taken to become that of=f-s
f grows to f+(f-s)=2f-s
3f-s=126
age of son f-s years ago =2s-f
3s-f=38
3f-s=126
8f=416
f=416/8=52 years
s=30