Correct Answer - Option 2 : 10 : 1
Total number of students = 1000
Total lecturers = (1/10) of 1000
⇒ 100
Number of male lecturer = 100 × (2/5)
⇒ 40
Number of female lecturer = 100 × (3/5)
⇒ 60
Number of lecturers present on Monday = 40 + 20
⇒ 60
Number of lecturers not present on Monday = 100 – 60
⇒ 40
Number of students present on Monday = 10 × 60
⇒ 600
Number of students not present on Monday = 1000 – 600
⇒ 400
Required ratio = 600 : 60
⇒ 10 : 1