Question
How many students appeared in at least two
exams? 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 at least two exams = 80 + 120 + 100 + 40 = 340
In a structured database, which data storage format would best support hierarchical data with varying levels of nested attributes?
Which of the following semantic HTML tags is best suited for defining a block of navigation links?
Which of the following best describes the role of data analysis in credit scoring within the finance industry?
In descriptive statistics, which of the following measures is least affected by extreme values (outliers)?
Which data transformation scales features to a range of 0 to 1?
In hypothesis testing, what does a p-value less than 0.05 typically indicate?
Which type of machine learning technique is best suited for supervised learning tasks?Â
Which of the following is the primary purpose of exploratory data analysis (EDA)?
Which of the following best represents semi-structured data?
A data analyst is tasked with forecasting quarterly sales for the upcoming year based on the last five years of sales data. Which of the following metho...
Relevant for Exams:
