Hi, I'm happy to help!
To solve this, we need to multiply the 60% by the amount of students.
75×60%
Percentages are always out of 100, so we can write 60% like this:
75×60%
75×0.60, or 75×0.6
Now, we just multiply these together.
75×0.6
45
So, 45 of the students are girls.
I hope this was helpful, keep learning! :D