Question

22. After 12 years Manojwill be 3 times as old as he was 4 years ago. Find his present age.​

Answer 1

Answer:

12 years

Step-by-step explanation:

Let the present age of Manoj be x

Age after 12 years = x + 12

Age 4 years ago = x - 4

As per the given condition

x + 12 = 3(x - 4)

x + 12 = 3x - 12

-2x = -12 - 12

-2x = -24

x = 12

Hence, Manoj's present age = 12 years

Answer 2

$\large\underline{\sf{Solution-}}$

Let assume that present age of Manoj be 'x' years.

After 12 years,

• Manoj age will be x + 12 years.

Before 4 years,

• Manoj age was x - 4 years

According to statement,

Manoj will be 3 times as old as he was 4 years ago

$\rm :\implies\:x + 12 = 3(x - 4)$

$\rm :\longmapsto\:x + 12 = 3x - 12$

$\rm :\longmapsto\:x - 3x= - 12 - 12$

$\rm :\longmapsto\: - 2x= - 24$

$\bf\implies \:x = 12$

Hence,

$\: \: \: \: \: \: \: \: \underbrace{ \boxed{ \rm \: Present \: age \: of \: Manoj \: is \: 12 \: years}}$

Basic Concept Used :-

Writing Systems of Linear Equation from Word Problem.

1. Understand the problem.

• Understand all the words used in stating the problem.

• Understand what you are asked to find.

2. Translate the problem to an equation.

• Assign a variable (or variables) to represent the unknown.

• Clearly state what the variable represents.

3. Carry out the plan and solve the problem.