There are 12 students working in the library if 3/4 of them are girls how many girls are working in the library

So 3/4 of 12

remember that 12=12/1

and if you ahve x/y times z/t that equals to (xz) / (yt) so

'of' means multiply

3/4 times 12/1 = (3 times 12) / (4 times 1) = 36/4=9/1=9

9 are working in the library

If you would like to know how many girls are working in the library, you can calculate this using the following steps:

3/4 of 12 students = 3/4 * 12 = 3 * 3 = 9 girls

Result: There are 9 girls working in the library.