The term independent of x in the binomial expansion of ${\left(\frac{2}{{\mathrm{x}}^2} - \sqrt{\mathrm{x}}\right)}^{10}$ is equal to ?

• 180

• 120

• 90

• 72

The numbers 4 and 9 have frequencies x and (x - 1) respectively. If their arithmetic mean is 6, then what is the value of x ?

• 2

• 3

• 4

• 5

What is the sum of the last five coefficients in the expansion of (1 + x)⁹ when it is expanded in ascending powers of x ?

• 256

• 512

• 1024

• 2048

The arithmetic mean of 100 observations is 40. Later, it was found that an observation ‘53’ was wrongly read as ‘83’. What is the correct arithmetic mean ?

• 39.8

• 39.7

• 39.6

• 39.5

If ∑x_i = 20, ∑x_i² = 200 and n = 10 for an observed variable x, then what is the coefficient of variation ?

• 80

• 100

• 150

• 200