1.  If in 1999, the population of village R increase by 10% while that of village Z reduces by 5% compared to that in 1997 and the percentage of population below poverty line remains unchanged for all the villages, then find the approximate ratio of population of village R below poverty line to the ratio of population of village Z below poverty line for the year 1999.
A. 2 : 1
B. 3 : 2
C. 4 : 3
D. 5 : 4

Answer: Option A

Explanation:

Let the total population of all the seven village in 1997 be N.
Then, population of village R in 1997
= 16% of N = 16N/100
and population of village Z in 1997
= 11% of N = 11N/100

Population of village R in 1999 
= { 16N/100 + (10% of 16N/100) }
= 1760N/10000

and population of village Z in 1999
= { 11N/100 - (5% of 11N/100)}
= 1045N/10000

Now, population of village R below poverty line for 1999
= 51% of 1760N/10000 
and population of village Z below poverty line for 1999
= 42% of  1045N/10000 

= 51% of 1760N/10000 / 42% of  1045N/10000 
= 51 x 1760  
    42 x 1045
= 2/1