question_answer

80% of students of a class took Statistics and 45% took Mathematics. If each student took Statistics or Mathematics and 40 took both, then total number of students in the class was

A) 160                  

B) 180      

C) 200                  

D) 225

Correct Answer: A

Solution :

Sol.      [a]              By Venn diagram, percentage of students having both Mathematics and Statistics = (80 + 45 - 100) % = 25% Let the total number of student be x. 25% of x=40 \[\therefore \,\,\,\,\frac{25}{100}\,x\,=\,40\] x = 160