Mathematics Tes...

Let X denote the number of scores which exceed 4 in 18, tosses of a symmetrical die. Consider the following statements:

1. The arithmetic mean of X is 6.

2. The standard deviation of X is 2.

Which of the above statements is/are correct?

Consider the following statement in respectdifferential equationa$\frac{a^{2}y}{a{x}^2}+\cos \left(\frac{ay}{ax}\right)=0$

1. The degree of the differential equation is not defined.

2. The order of the differential equation is 2.

Which of the above statements is/are correct?

Given that C(n, r) : C(n, r + 1) = 1 : 2 and C(n, r + 1) : C(n, r + 2) = 2 : 3.

What is n equal to?

Let X be the set of all citizens of India. Elements x, y in X are said to be related if the difference of their age is 5 years. Which one of the following is correct?

The sum of the series formed by the sequence 3, √3, 1 …….. upto infinity is:

The determinant of an odd order skew symmetric matrix is always:

Evaluate-${\tan }^{-1}\left(\frac{3}{4}\right)+{\tan }^{-1}\left(\frac{1}{7}\right)$.

A straight line passes through (1, –2, 3) and perpendicular to the plane 2x + 3y – z = 7.

What are the direction ratios of normal to plane?

The variance of number$x^1,x^2,x^3,..........x^n$, is V. Consider the following statement:

1.If every x_iis increased by 2, the variance of the new set of numbers is V.

2. If the numbers x_iis squared, the variance of the set is V²

Which of the following statement is/are correct ?