A father said to his daughter when I was of your age you were 4 years old.when you will be of my age I will be 79 years old.what is the present age of them
Answers
Let fathers age be F & daughter's age be D
Difference = F-D................................................................①
THIS DIFFERENCE WILL NEVER CHANGE
"when i was your age, you were 4 year old"
Fathers age=D Daughter's age =4
difference = D-4................................................................②
D-4=F-D
F=2D-4--------------------------------------------------------------- ③
When i will be 79 you will be my present age
now, Father age =79 Daughter's Age=F
79-F=F-D
79+D=2F
79+D=2(2D-4)
79+D=4D-8
3D=87
D=29
FROM equation 3, F=2D-4
⇒F=2*29-4=54
ᖴᗩTᕼEᖇ'ᔕ ᗩGE=54, ᗪᗩᑌGᕼTEᖇ'ᔕ ᗩGE=29
Read more on Brainly.in - https://brainly.in/question/5015811#readmore
Let us consider f = father's present age
let d = daughter's present age
So, the difference in their ages = d-4
Now,
f - 2(d-4) = 4
f - 2d + 8 = 4
f - 2d = 4 - 8
f = 2d - 4
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
The answer is 54 years