Question

In Kolkata consisting of three localities Salt Lake, South Kolkata and Rajarhat the population of the three localities Salt Lake, South Kolkata and Rajarhat are in the ratio 9 : 8 : 3. In Salt Lake, 80% of the people are literate, in South Kolkata, 30% of the people are illiterate. If 90% people in Rajarhat are literate. Find the percentage literacy in these three localities in Kolkata.

1. 77.5%
2. 85%
3. 88.2
4. 72.5%
5. 75%

Answer 1

Correct Answer - Option 1 : 77.5%

Let the population of Salt Lake = 9x, 
 

The population of South Kolkata = 8x, and 
 

The population of Rajarhat = 3x
 

The total population of these three localities = 9x + 8x + 3x = 20x
 

The number of literate in Salt Lake = 80% of 9x = 7.2x
 

The number of literate in South Kolkata = 70% of 8x = 5.6 x
 

The number of literate in Rajarhat = 90% of 3x = 2.7x
 

The total number of literate in these three localities = 7.2x + 5.6x + 2.7x = 15.5x

 

Hence. Required percentage =	15.5 x	× 100 = 77.5%
	20x

Therefore, option (1) is correct.