In an examination 80% students passed. if 15 less have appeared and 10 less have passed, the ratio of passers to failures would have been 5:1. how many students passed and how many appeared in examination?

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MathPhys MathPhys · Answer 1 · 2020-01-10T17:19:08+01:00

Answer:

60 students passed, and 75 appeared in examination.

Step-by-step explanation:

Let's say s is the total number of students and p is the number of students who passed.

80% of the students passed, so:

0.8 s = p

If there were 10 less passers, and 15 less students (5 less failures), then the ratio of passers to failures would be 5/1.

(p − 10) / (s − p − 5) = 5 / 1

Simplify the second equation:

p − 10 = 5 (s − p − 5)

p − 10 = 5s − 5p − 25

6p = 5s − 15

Substitute the first equation.

6 (0.8 s) = 5s − 15

4.8 s = 5s − 15

0.2 s = 15

s = 75

p = 0.8 s

p = 60

60 students passed, and 75 appeared in examination.