Question

Assume there are four families in a country. The average per capita income of these families is $\text{Rs}5000$. If the income of three families is $\text{Rs}4000$, $\text{Rs}7000$ and $\text{Rs}3000$ respectively, what is the income of the fourth family?

• A. $\text{Rs 7500}$
• B. $\text{Rs 3000}$
• C. $\text{Rs 2000}$
• D. $\text{Rs 6000}$

Answer 1

The correct option is D

$\text{Rs 6000}$

Explanation for the correct option:

Given that there are four families and average per capita income of these families is $Rs5000$. The income of three families is $Rs4000$, $Rs7000$ and $Rs3000$ respectively

Let the income of the fourth family be $RsX$

Let the total income of all families be $T$ and number of families be $N=4$

The average per capita income $PI$ is given as $PI=\frac{T}{N}$

Substituting the values we get

$5000=\frac{4000+7000+3000+X}{4}$

$\Rightarrow$$20000=14000+X$

$\Rightarrow$ $X=Rs6000$

Thus the income of the fourth family is $Rs6000$.

Hence option(D) is the correct option.