Since student one is 1/4 you would have to multiple 4 times 25 to equal a hundred, therefore you would multiple 25 to the top to keep the equation equal, the percent would be 25%.
Student 3 did 13/20 and 20 times 5 equals 100 so then to balance it you do 13 times 5 which would be 52 & not 65 so it would be 52% for that student.
Student two did 7/10 and 10 times 10 is 100 so again to balance it 7 times ten is 70 which is 70%, so student two is the correct answer.
