Find the number of students who took an exam if the ratio of those who passed to those who failed in the exam was 10 : 3. If 40 more students had taken the exam and 10 less had failed, then the ratio of those who passed to those who failed in the exam would have been 5 : 1.
Find the number of students who took an exam if the ratio of those who passed to those who failed in the exam was 10 : 3. If 40 more students had taken the exam and 10 less had failed, then the ratio of those who passed to those who failed in the exam would have been 5 : 1. Correct Answer 260
Given:
The ratio of passed and failed students = 10 : 3
Calculation:
Let the number of students who took the exam be 13x
So, the number of students who passed = (10/13) × 13x = 10x
Also, the number of students who failed = (3/13) × 13x = 3x
If 40 more students take the exam,
Then total number of students having taken the exam = 13x + 40
If 10 students less fail, then failed students = 3x – 10
Now, the number of passed students = 13x + 40 – (3x – 10) = 10x + 50
So, the new ratio of passed and failed candidates becomes:
(10x + 50)/(3x – 10) = 5/1
⇒ x = 20
∴ The total number of students who took the exam = 13 × 20 = 260