1
JEE Main 2022 (Online) 28th June Evening Shift
Numerical
+4
-1

Suppose a class has 7 students. The average marks of these students in the mathematics examination is 62, and their variance is 20. A student fails in the examination if he/she gets less than 50 marks, then in worst case, the number of students can fail is _________.

2
JEE Main 2022 (Online) 28th June Morning Shift
Numerical
+4
-1

The mean and standard deviation of 15 observations are found to be 8 and 3 respectively. On rechecking it was found that, in the observations, 20 was misread as 5. Then, the correct variance is equal to _____________.

3
JEE Main 2022 (Online) 25th June Evening Shift
Numerical
+4
-1

If the mean deviation about the mean of the numbers 1, 2, 3, .........., n, where n is odd, is $${{5(n + 1)} \over n}$$, then n is equal to ______________.

4
JEE Main 2021 (Online) 31st August Morning Shift
Numerical
+4
-1
The mean of 10 numbers 7 $$\times$$ 8, 10 $$\times$$ 10, 13 $$\times$$ 12, 16 $$\times$$ 14, ....... is ____________.