In an examination 200 students passed in both physics and chemistry and 40% of the class passed in physics and 60% passed in chemistry. If 10% of the class failed in both the sunjects then what is the total number of students of the class?

1. A Option A: 1000
2. B Option B: 800
3. C Option C: 900
4. D Option D: 2000

How we write and check questions