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.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 260
|
Understanding |
Application |
|
Ratio of those who passed to those who failed in the exam was 10 : 3. |
Suppose the number of students who passed and number of students who failed in the exam are 10x and 3x respectively. |
|
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. |
So, Total students = 13x + 40 Number of students who failed = 3x – 10 So, Number of students who passed = (13x + 40) – (3x – 10) = (10x + 50) So, (10x + 50) : (3x – 10) = 5 : 1 10x + 50 = 15x – 50 5x = 100 x = 20 So, Total number of students who took exam = 13x = 260 |