Question

The sum of father's and son's ages is 30 years. If father's age is 28 years, what's the son's age?

• A. 1 year
• B. 2 years
• C. 3 years
• D. 4 years

Answer 1

The correct option is B 2 years

Now, let the age of son be x years.

As given, sum of the ages of father and son is 30 years.

Hence the algebraic expression is given as
$x+28=30$

Using trial and error method,

Case 1:

Putting x = 1,
LHS = 1 + 28 = 29
Hence, LHS is not equal to RHS.

Case 2:

Putting x = 2,
LHS = 2 + 28 = 30
Hence, LHS is equal to RHS.

$\therefore$ The age of son is 2 years.