Question

Aaron is 5 years younger than Ron. Four years later, Ron will be twice as old as Aaron. Find the present age of Aaron.

• A. 3
• B. 7
• C. 2
• D. 1

Answer 1

The correct option is D 1

Let Ron’s age be $x$
Then, Aaron’s age will be $x-5$

After 4 years,
Ron’s age $=x+4$
Aaron’s age $=x-5+4=x-1$

According to the question,
After 4 years,
Ron’s age = 2$\times$Aaron’s age
$x+4=2(x-1)$

If x = 1,
LHS, $x+4=1+4=5$
RHS,$2(x-1)=2\times (1-1)=0$
LHS $\ne$ RHS

If $x=2$,
LHS, $x+4=2+4=6$
RHS,$2(x-1)=2(2-1)=2\times 1=2$
LHS $\ne$ RHS

If $x=3$,
LHS, $x+4=3+4=7$
RHS, $2(x-1)=2\times (3-1)=2\times 2=4$
LHS $\ne$ RHS

If $x=4$,
LHS, $x+4=4+4=8$
RHS,$2(x-1)=2(4-1)=2\times 3=6$
LHS $\ne$ RHS

If$x=5$,
LHS, $x+4=5+4=9$
RHS, $2(x-1)=2\times (5-1)=2\times 4=8$
LHS $\ne$ RHS

If $x=6$,
LHS, $x+4=6+4=10$
RHS, $2(x-1)=2\times (6-1)=2\times 5=10$
LHS = RHS
Therefore, x = 6

Therefore, Ron’s age = x = 6 years
Hence, Aaron’s present age = x - 5 = 6 - 5 = 1 year