Questions & Answers

Question

Answers

A. 4years

B. 8years

C. 10years

D. 6years

Answer
Verified

First let the age of first child is x years

Now the age of second child is $x + 3$

Age of third child $x + 6$

Age of fourth child $x + 9$

Age of fifth child $x + 12$

And we known that the sum of the ages of five children born at the intervals of 3year is 50 years

So, we have

Age of first child + age of second child + age of third child + age of fourth child + age of fifth child = 50 years

After Putting the values, we get

$x + x + 3 + x + 6 + x + 9 + x + 12 = 50$

Add the variables and consent term

$5x + 30 = 50$

$5x = 50 - 30$

$5x = 20$

$x = \dfrac{{20}}{5}$

$x = 4$

Now we have the value of x

So the age of first child

$x = 4$years

Age of second child

$= x + 3 = 4 + 3$

= 7 years

Age of third child

$= x + 6 = 4 + 6$

= 10 years

Age of fourth child

$= x + 9 = 4 + 9$

= 13 years

Age of fifth child

$= x + 12 = 4 + 12$

= 16 years

So now the youngest child is 4 years.

In this question we used the concept of Linear equation in one variable.

Linear equation in one variable has only one variable and the linear equation in two variables has two variables.