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