If four students are made to sit in a row, then 7 don't have seats. If 7 students are made to sit in a row, then two rows are empty. How many students have to sit a row such that each row has equal number of students and all students are seated?  Choices.
A) 0  B) 1  C) 4  D) 5  E) 9
Let there be a rows.   Then 4a + 7 = 7(a-2) [equating the number of students]   =&gt; a= 7   and total number of students = 35   Therefore 5 students much sit in each row such that each row has an equal number of students and all students are seated.   Option (5)
<result>D</result>
If four students are made to sit in a row, then 7 don't have seats. If 7 students are made to sit in a row, then two rows are empty. How many students have to sit a row such that each row has equal number of students and all students are seated?