Translation of Word Problems into Equations

To translate a word problem into an algebraic equation and solve it, the following are the steps:

1. Read the questions carefully and then decide what the unknown number is.
2. Where necessary, change all the units of measurement to the same unit.
3. Use a letter to represent the unknown
4. Use the information provided to write the required equation.
5. Solve the equation as usual.
6. Use the solution obtained to answer the questions in words.
7. You can check your answer as usual.

Example 5.3.1:

The age of a father is thrice the sum of the ages of his two sons. After 5 years his age will be twice the sum of their ages. Find the present age of the father.

Solution

Step 1: Let us understand the given information. There are two sets of information given in the question.

a) The age of the father is thrice the sum of the ages of his two sons (At present).
b) After 5 years, his age would be twice the sum of their ages (After 5 years).

Step 2: Target of the question = Present age of the father.

Step 3: Introduce the required variable for the information given in the question.

Let x be the present age of the father

Let y be the sum of the present ages of two sons.

Clearly, the value of x is to be found because that is the target of the question.

Step 4:

Translate the given information as a mathematical equation using x and y.

First Information: The age of the father is thrice the sum of the ages of his two sons.

Translation i: The age of the father =  x

x  =  thrice the sum of the ages of his two sons = 3y

Equation related to the first information using x and y is   

x  =   3y  ___________ (i)