Question

A father said to his son, "I was as old as you are
at the present at the time of your birth". If the
father's age is 38 years now, the son's age five
years back was????

Answer 1

For these questions the tricky part is to find the equation that needs solving.
In order to find it first you will need to decide what are you looking for. In other words what is x?

Answer 2

Any idea? How should we define x?

Answer 3

present age of son?

Answer 4

Can be. Will you try to write and equation with it

Answer 5

no:(

Answer 6

I was as old as you are
at the present at the time of your birth

This needs to be translated to maths

Answer 7

yes and this is the main problem.....actually i know the ans...but not the logic:(

Answer 8

OK no problem. So the father is 38 and the son is x years old.
How old was the father when his son was born? Use 38 and x

Answer 9

2x=38 but how???i dont know

Answer 10

First just figure this out: How old was the father when his son was born?

Answer 11

I will give you a hint: my dad is 62 and I am 30. When I was born my dad was 32. How did I calculate this?

Answer 12

19 years....but that's the point where i get confused....how can we find this by que that fathers age is double than that of his son..

Answer 13

Can you answer my last question?

Answer 14

ok let me think about it

Answer 15

Sorry rosy I have to go for 5 minutes. Will be back later

Answer 16

adding 32 in your age

Answer 17

ok fine

Answer 18

my dad is 62 and I am 30.
*** adding 32 in your age ***
yes because 30 + 32 = 62

now if we add -30 to both sides , we could also say
32 = 62 - 30

in other words, 30 years ago, the father was 32.

Answer 19

father's age minus son's age is the age of the father when the son was born.

Answer 20

I am back and phi is showing you the correct logic

Answer 21

now notice we can say the same thing with letters
my dad is 62 and I am x

dad's age when son born is 62 - x

Answer 22

but in my que 38-x=?

Answer 23

so now try to figure out father's age when
father's age is 38 years now
son's age now is x years old

how old was the father when the son was born ?

Answer 24

38-x is the age of the father when the son was born.

Answer 25

I was as old as you are now

in other words,
father's age (38-x) is the same as the son's age now (x)
they are equal.

Answer 26

and how can we find the value of x?

Answer 27

oh ok...thank u:)

Answer 28

can you write the equation?

Answer 29

you should get
38-x = x

Answer 30

but 62-30 not equal to 30 in andras exmp

Answer 31

again confused:(

Answer 32

andras uses different numbers.

The thing that is the same is this:

age of father minus age of son now equals age of father when the son was born.

Answer 33

it turns out andras is not the same age as his father's age when andras was born.

but in your problem, they tell us: son's age now ( that is, x)
is the same as the father's age back then (38 - x)

Answer 34

to get "unconfused" , convince yourself that if the father is 38 now, x years ago, he was 38-x (years old)

Answer 35

if the father is 38 now, x years ago, he was 38-x (years old)
does that part make sense?

Answer 36

thaks a lot to both andras and phi....now it is clear to me

Answer 37

once you get to
38-x= x
you solve by add +x to both sides
38-x+x = x+x

-x + x on the left side is 0. on the right side, x+x is 2x
38= 2x
now divide both sides by 2 to get
19= x

in other words, the son is 19 years old.
the father is 38 years old. 19 years ago (when the son was born), the father was 38-19= 19
we see the father was 19 years old when his son was born... the same age as his son is *now*

Answer 38

Great :)