Mathematics - Online Test

Q1. If the coefficient of variation between x and y is 0.28, covariance between x and y is 7.6, and the variance of x is 9, then the S.D. of the y series is
Answer : Option C
Explaination / Solution:



Q2. Consider the differential equation  Which of the following is a solution to this differential equation for x > 0?
Answer : Option C
Explaination / Solution:



Q3. If A = { 1, 2, 3}, then the relation R = {(1, 2), (2, 3), (1, 3)} in A is
Answer : Option B
Explaination / Solution:

A relation R on a non empty set A is said to be transitive if x Ry and y Rz ⇒xRz, for all x ∈ R. Here , (1, 2) and (2, 3) belongs to R implies that (1, 3) belongs to R.

Q4. DELETE IT 
Answer : Option B
Explaination / Solution:





Q5. The lines x + ( k – 1) y + 1 = 0 and are at right angles if
Answer : Option A
Explaination / Solution:

If the lines are at right angles to each other, then the product of their slopes = -1. Slope of any line = -(coefficient of x/coeffiecient of y)

Therefore slope of line 1 = -(1/(k-1)

Slope of line 2 = -2/k2

Therefore  X  = - 1

That is k2 (k-1) = -2

i.e; k3 - k2 +2 = 0

On factorizing we get (k+1)(k2 -2k - 2) = 0

This imlpies k+1 is a factor, hence k = -1

Hence they are at right angles if k = -1


Q6. The compound statement p→(∼p∨q) is false , then the truth values of p and q are respectively
Answer : Option B
Explaination / Solution:

     since T->F is false.


Hence q=F.

So p=T and q=F


Q7.

 is equal to


Answer : Option B
Explaination / Solution:



Q8. If a vector  is expressed in component form as  then the magnitude of the vectorr   is
Answer : Option D
Explaination / Solution:



Q9. Given that E and F are events such that P(E) = 0.6, P(F) = 0.3 and P(E ∩ F) = 0.2, find P (E|F) and P(F|E)
Answer : Option A
Explaination / Solution:

We have ,
P(E) = 0.6, P(F) = 0.3 and P(E ∩ F) = 0.2, then ,

Q10.  equals
Answer : Option A
Explaination / Solution:

we know that sin1x+cos1x=π2sin(sin112+cos112)=sin(π2)=1