There are 12 students working in a library if three fourth of them are girls how many girls are working in the piano

I don’t really get your question, because you said that ¾ of them are girls, Then how many girls are working in the piano? You did not stated the question well. However, I will try to answer this base on my understanding. There are a total of 12 students that works in the library. IF ¾ of them are girls: => 12 / 4 = 3 *3 = 9 => 9 of them are girls and 3 of them are boys. Thus, how many girls are working in the piano. The probability is 9, there might be 9 girls working in the piano, or less than 9. Since you did not mention how many girls worked in different part of the library.

Ibelieve that c. recording would work best.