Question

father told his Son when I am in your
age you were 4 years .when you comes
to my age I will be 79 years old.
Now what is the age of father and
son?
​

Answer 1

Father says to his daughter, "When I was your age, you were 4 years old. When I will be 79 you will be my present age."

What are their present ages.

:

let f = father's present age

let d = daughter's " "

:

"When I was your age, you were 4 years old."

(d-4) = the difference in their ages

therefore we can write an equation

f - 2(d-4) = 4

f - 2d + 8 = 4

f - 2d = 4 - 8

f = 2d - 4

:

 

" When I will be 79 you will be my present age."

f = 79 - (d-4)  

f = 79 - d + 4

f = 83 - d

Replace f with (2d-4)

2d - 4 = 83 - d

2d + d = 83 + 4

3d = 87

d = 87/3

d = 29 yrs is the daughter's age

then

83 - 29 = 54 yrs is fathers age

:

:

Check this: 54 - 29 = 25 years is the difference in their ages

When Dad is daughter's age (29), daughter will be 4

Answer 2

let f is equals to father letter T is equals to 3 minus 4 the difference in there is there for F - 2 bracket - 4 bracket is equal to 4 x minus 2 + 8 is equals to 4 x minus 2 b is equals to 4 minus 8 is equals to F = 22 degree minus 4 then f is equals to 79 - bracket 1 - 4 is equals to F = = 27 - 3 + 4 = 283 - 2B - 4 is equals to 8332 D + b = 23 + 4 CD is equals to 37 b is equals to 37 upon 3 83 - 29 is equal to 54 years and father is 59 - 29 is equals to 25 so the father is 29 and daughter 4