Question
How many students appeared in exam X or in exam
Z? Study the following information carefully and answer the given questions: There are 1000 students in a college. Out of 1000 students some appeared in exams ‘X’, ‘Y’ and ‘Z’ while some not. Number of student not appeared in any exam is equal to number of students appeared in exam ‘Z’ only. Number of students appeared in exam ‘Y’ is 360. Ratio of number of students appeared in exam ‘X’ and ‘Y’ only to number of students appeared in exam ‘Y’ and ‘Z’ only is 2:3. Number of student appeared in exam ‘X’ and ‘Z’ both is half of number of students appeared in only exam ‘Z’. Number of students appeared in exam ‘X’ only is 50% more than number of students appeared in ‘Y’ only. Number of students appeared in all the three exam is 4% of the total number of students in the college. Number of students appeared in ‘Y’ exam only is same as number of students appeared in ‘Y’ and ‘Z’ only.Solution
Total students = 1000 Let, students appear in exam Z only = a Total students appeared in exam Y = 360 Ratio of number of students appeared in exam X and Y only to students appeared in exam Y and Z only = 2:3 Students appeared in exam X and Z both = a/2 Number of students appeared in all three exams = (4/100) × 1000 = 40 Number of students appeared in Y exam only = No. of students appeared in Y and Z only = 3x Number of students appeared in exam X and Y only = (2/3) × 3x = 2x Now, 2x + 3x + 3x + 40 = 360 ⇒ x = 40 And, 12.5x + a + a/2 + a = 1000 => 5a/2 = 500 ⇒ a = 200 Students appeared in exam X or in exam Z = 180 + 60 + 40 + 80 + 200 + 120 = 680
A data analyst is tasked with evaluating customer feedback from a population of 1,000,000 survey responses. Why is sampling an essential technique in th...
What is the result of the following SQL query?
 SELECT department, COUNT (employee_id)Â
FROM employees GROUPBY department HAVING COUNT (e...What is the primary difference between recursion and iteration in programming?
In Excel, you want to summarize sales data by region and product category, displaying the sum of sales for each combination. Which feature should you us...
A data analyst at an insurance company is tasked with assessing the probability of fraudulent claims by analyzing customer transaction data and claim hi...
A hospital uses a data-driven approach to improve patient care. They identify that patients with similar conditions respond differently to treatments b...
In a virtual memory system, a process requests a page that is not currently in memory, triggering a page fault. Which of the following is the most optim...
Which of the following is a key difference between structured and unstructured data?
In the context of risk modeling for credit scoring, which of the following factors is least likely to be used in predicting a person’s creditworthines...
Which sampling technique is most suitable when a population has distinct subgroups that should be represented proportionally?