The mean of numbers in A.P. 2, 4, 6, 8, ……, 40 is :

1. $\dfrac{40 + 2}{2}$

2. $\dfrac{20}{2}(2 + 40)$

3. $\dfrac{10}{2}$ (2 + 40)

4. 840

The inter quartile range for the given ogive is :

1. 42

2. 32

3. 44

4. 54

The numbers 10, 12, 14, 16, 17 and x are in ascending order. If the mean and median of these observations are same, the value of x is :

1. 16

2. 14

3. 54

4. 21

The median of first six prime numbers is :

1. 5

2. 7

3. 6

4. 7.5