1
NDA 2019 Paper 1
MCQ (Single Correct Answer)
+2.5
-0.83
If all the natural numbers between 1 and 20 are multiplied by 3, then what is the variance on the resulting series?
2
NDA 2019 Paper 1
MCQ (Single Correct Answer)
+2.5
-0.83
The mean of 100 observations is 50 and the standard deviation is 10. If 5 is subtracted from each observation and then it is divided by 4, then what will be the new mean and the new standard deviation respectively?
3
NDA Mathematics 14th September 2025
MCQ (Single Correct Answer)
+2.5
-0.833
The standard deviation of 100 observations is 10. If 20 is added to each observation, then what will be the new standard deviation?
4
NDA Mathematics 14th September 2025
MCQ (Single Correct Answer)
+2.5
-0.833
The frequency distribution of the marks obtained by students in a Science examination is given below:
What is the arithmetic mean?
| Marks | 5-15 |
15-25 |
25-35 |
35-45 |
| Number of students |
20 | 30 | 30 | 20 |
NDA Subjects
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Sets, Relations and Functions Logarithms Quadratic Equations and Inequalities Sequence And Series Binomial Theorem Matrices Determinants Permutations and Combinations Probability Complex Numbers Vector Algebra Three Dimensional Geometry Statistics
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