In an examination, 90% of the students passed and 600 students failed. How many students appeared for the examination?

Correct option is C

Given:

 90% of the students passed

600 students failed.

Solution:

Let Total students = 100x

90% students passed in 100x = 90x

So that failed students = 100x - 90x = 10x

Then, 

10x = 600

x = $$\frac{600}{10}$$

x = 60 

Now,

Total students  = 100x 

Total students  = 100 × 60

Total students  = 6000

Thus, option (c) is correct.