Answer : 1. "बिहार"
Explanation :

1. According to the 2011 census, the total population of Bihar is 104,099,452, of which males and females are 54,278,157 and 49,821,295 respectively.

2. According to the 2011 census, the total literacy rate of Bihar is 61.80 per cent.

3. In this, male literacy is 71.20% while female literacy is 51.50%.

4. According to the 2011 census, Bihar is the least literate state.

5. Hence, according to the 2011 census, Bihar ranks first in terms of the lowest literacy rate.

6. Kerala is the most literate state in the country with a literacy rate of 93.91%.