ln an examination, the number of students who passed and the number of students who failed were in the ratio 25 : 4. If one more students had appeared and passed and the number of failed students was 3 less than earlier, the ratio of passed students to failed students would have become 22 : 3. What is the difference between the number of students who, initially, passed the examination and the number of students who failed the examination?

A. 132

B. 174

C. 126

D. 150

Answer: Option C

Solution(By Examveda Team)

Ratio of passed student to fails students = Pass : Fail = 25x : 4x
Total number 25x + 4x = 29x
New ratio of passed student to fails students = Pass : Fail = 22x : 3x = 25x
$$\frac{{{\text{Fail}}}}{{{\text{Total}}}} = \frac{{4x - 3}}{{29x + 1}} = \frac{3}{{25}}$$
100x - 75 = 87x + 3
13x = 78
x = 6
So, the difference is = 25x - 4x
= 21x
= 21 × 6
= 126