Question

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





(a)`7500 (b) `3000 (c) ` 2000 (d) `6000

Answer 1

Let Income Of Fourth Family = x

Average per capita income = Total Income      4000+7000+3000+x
                                               ------------------ =  ----------------------------
                                               Total Families                    4
  5000=4000+7000+3000+x 
            ---------------------------
                          4       
   5000*4=14000+x

20000-14000=x

x= 6000

Hence, Income of fourth family = 6000

Answer 2

Given: There are four families in a country. The average per capita income of these families is 5000. The income of three families is 4000,7000 and 3000 respectively.

To find: Income of the fourth family

Solution: "Average per capita income is a measure of the average income earned by a population."

The average per capita income of the families is given by the sum of incomes of the families divided by the number of families.

Income of the first family= 4000

Income of the second family= 7000

Income of the third family= 3000

Let the income of the fourth family be x.

Sum of incomes

= 4000+7000+3000+x

= 14000+x

Number of families=4

Average per capita income

= Sum of incomes/Number of families

= 14000+x/4

But the average per capita income is given as 5000 in the question.

Therefore,

14000+x/4 = 5000

=> 14000+x= 5000×4

=> 14000+x = 20000

=> x = 20000-14000

=> x = 6000

Therefore, the income of the fourth family is option (d) 6000.