Aptitude - Problems on Ages - Discussion

The respective ratio of the present age of A and B is 8:9. The sum of their ages is 68. What will be the respective ratio of their ages 10 years hence?

It can also be solved using formula : bt(c - d)/ (ad - bc).

Where a = 5, b = 4, c = 11 and d = 9.

t = 3.

4* 3(11 - 9)/(5*9 - 4*11)= 12* 2/ 45- 44.

= 24/1= 24. So the answer is 24.

@Murugan k.

QUE--> 5 years ago A age was 3 times as old as B . If A is 30years older than B .The present age of A?

Answer--> Before 5 years A=3B.

So after 5 years A's age increases by 5 so does the B's age. We get
A+5 = 3B+5-----------(eqn1)(this is present because I have increased 5yr from past).

A is 30 year older than B so A=B+30--------(eqn2),

Since we have to find the value of A we convert(eqn2)cas B=A-30--------(eqn3).

Now substitute (eqn3)in(eqn1).

A+5 = 3(A-30)+5.

A = 3A-90.

2A = 90.

A = 45 and B = 15.

@Iti and @Sriteja.

Hi friends since they have asked as 3 years ago we have to subtract it and not add.

A+B+C = 80,

Before 3 years or 3 years ago means,

A-3.
B-3.
C-3.

80-9 = 71.

So b4 3 years A+B+C = 71.

@Agila.

Given Ratio 5:4----->(1).
Difference between the ratio is 1.
After three years 11:9---->(2).
Difference between the ratio is 2.
Both the ratio difference are not same.

So multiply (1) by 2, we get 10:8.
||ly multiply (2) by 1, we get 11:9. now the difference are same.
Anand's present age=8*3=24 year.

How here 8 will be please tell me?

How did 5x+3/4x+3 = 11/9.

Hai @Iti the problem can be solved as,

a+b+c=80 then after 3 years (a+3)+(b+3)+(c+3)=80+9=89

The given problem can be solved in other method as,

Given x/y=5/4;
After 3 years (x+3)/(y+3)=11/9;
Solving 9x-11y-6=0;
4x-5y=0;

We get x=30 y=24 Hence answer is 24 years.

The total ages of the a, b and c 80 years. What was the total of their ages three year ago ?

Ratio after 3 yrs ,

5x+3 11
----- = --
4x+3 9

9(5x+3)=11(4x+3)
45x+27 = 44x+33
45x-44x+27=33
x+27=33
x=6.

Present age of anand=4*6 = 24.

Remember @agila the ratio are not for a period.