A group of women in a society decided to execute interior and exterior decoration of the society in a week’s time. Since 11 women dropped out every day from the second day, the entire decoration was completed on $$12^{th}$$ day. How many women participated at the beginning ? (Answer to the nearest integer)

Let x be the number of women who decided to execute the interior and exterior decoration of the society in a week’s time

Let the efficiency of each of them be 1

Total work = 7x

Number of women who worked on first day = x

Number of women who worked on second day = x-11

Number of women who worked on third day = x-22

....

On similar lines, the number of women who worked on $$n^{th}$$ day = x-(n-1)11

Number of women who worked on day 12=x-121

x+x-11+x-22+........x-(n-1)11 = 7x

12x-(11+22+....121)=7x

5x=$$\ \frac{\ 12}{2}\left(2\times\ 0+11\times\ 11\right)$$

x=145

C is the correct answer.