Rahim is 6 years older than David and David is 8 years older than Amar. After 8 years, if Rahim will be twice as old as Amar. then 4 years ago, David’s age was

Let the present age of Rahim $$=x$$ years

So, the present age of David$$=x-6$$

and the present age of Amar$$=x-6-8=x-14$$years

After the 8 years, age of Rahim will be $$x+8$$

After the 8 years, age of Amar will be $$x-14+8=x-6$$

As per the condition given in the question, $$x+8=2(x-6)$$

Hence, $$2x-x=12+8$$

$$x=20$$years

Hence, the present age of David $$=20-6=14$$years

4 years ago, the age of David $$=14-4=10$$years.