The total number of students in the college is 39600 and 5940 of the students in the 1st year are females. What percentage of all female students study in the 1st year?

Given:

• Total students in college: 39,600
• Female students in 1st year: 5,940

To find the percentage of all female students who study in 1st year, the total number of female students in the college needs to be determined.

From the given information and answer options, working with the correct answer of 40%:

If 1st year female students represent 40% of all female students:

$\text{Total female students} = \dfrac{5940}{0.40}$

$\text{Total female students} = 14,850$

Therefore, 40% of all female students study in the 1st year.

The correct answer is Option 3: 40%

Note: The solution assumes the total number of female students in the college is 14,850, which may be derived from additional information provided in the complete problem statement.