In an examination, 35% students failed in one subject and 42% failed in the other subject, among these 30% failed in both the subjects. If total number of students is 2500 then how many students passed only in one subject?

Correct option is B

Given:

Total number of students = 2500

35% students failed in one subject

42% students failed in the other subject

30% students failed in both subjects

Solution:

Students who failed in the first subject = 35% of 2500 = $$\frac{35}{100}$$​×2500 = 35×25 = 875

Students who failed in the second subject = 42% of 2500 = $$\frac{42}{100}$$​×2500 = 42×25 = 1050

Students who failed in both subjects = 30% of 2500 = $$\frac{30}{100}$$​×2500 = 30×25 = 750

Students who passed only the first subject = 875 - 750 = 125

Students who passed only the second subject = 1050 - 750 = 300

Thus, the total number of students who passed only in one subject is:

125 + 300 = 425