Aptitude - Problems on Ages - Discussion

It's so simple!

The value of x is ''8'' so 4 x is (4(8) + 16)/(8 + 16) and you get 48/24 = 2.

A is 2 years older than C and B is 2 years younger than C. The ratio of A's 6 years ago and B's 8 years ago is 6 : 5. Find C's present age.

Father F and Rohit R.
So, F = 3R + R = 4R.
After 8 years,
F + 8 = 2 1/2 (R + 8) means, F + 8 = 5/2 (R + 8).

So, 2(F + 8) = 5R + 40,
2(4R + 8) = 5R + 40,
8R + 16 = 5R + 40,
3R = 24,
R = 8.

Rohit's present age = 8 years.
After 16 years of present day (8 + 8).
Ratio would be F + 16/ R + 16.
So, 4R + 16/R + 16,
4(8) + 16/8 + 16 = 48/24 = 2.

You can also solve this problem by taking son's age as x and father's age as y. First, y = 4x as it is 3 times 'more' than that of his son. Then after 8 years son's age will be x+8 and father's age will be y+8=5/2(x+8) after solving you will get x = 8 and y = 32. Then after 16 years let father be n times of son's age i.e y + 16 = n(x + 16).

or 32 + 16 = n(8 + 16)
[putting x = 8 and y = 32]
or 48 = 24n,
or n = 2.

Therefore father is 2 times his son's age after 16 years.

How required ratio 4x + 16/x + 16 come?

@Yalleswari.

As per the statement, x + 3x.
After 8 years, he would be 2 and a half times of his son.

So, x + 3x + 8 = x + 8.
4x + 8 = x + 8.
(4x + 8 ) = 5/2(x + 8).

We get, 8x + 16 = 5x + 40 => 3x = 24.
x = 8.

After further 8 years,

So add 8 to the equation 4x + 8 + 8 = x + 8+ 8.
4x + 16 = x + 16.

So the ratio is, (4x + 16)/(x + 16) = 48/24.
=> 2 years.

Let the age of son be x then age of father will be 4x so we have ratio of father and son equals to 4x:x again after 8 years this becomes 5/2x:x as we all know that difference of age remains same then to make it same multiply above by 2 so that it becomes 5x:2x, therefore in 8 years 4x becomes 5x hence x is equal to 8 putting the value we get the age equal to 40 and 16 respectively and after 8 more years it will become 48 and 24 and hence father's age will be twice of son.

How you are getting 5/2?

Which has 1/2?

@Rekha.

2 and half times means 5/2 times.

Guys! It's three times more that mean 4x if it would be three times then we used 3x.