Mathematics - Online Test

Q1. S.D. of a data is 6. When each observation is increased by 1, then the S.D. of new data is
Answer : Option D
Explaination / Solution:


so it depends only on number of observations not on individual observations.


Q2.

Let f (x) =  then f (x) is strictly decreasing in


Answer : Option D
Explaination / Solution:




Hence , f is strictly increasing on [1,3].

Q3. A relation R on a non – empty set A is an equivalence relation iff it is


Answer : Option B
Explaination / Solution:

By definition of Equivalence Relation,a relation is said to be equivalence if it is reflexive,symmetric and transitive

Q4.
Answer : Option D
Explaination / Solution:

 because , the value of the determinant is zero only when , the two of its rows or column are identical., Which is possible only when Either x = 3 or x = 4 .

Q5. The distance between the parallel lines 4x + 3y + 11 = 0 and 8x + 6y = 15 is
Answer : Option A
Explaination / Solution:

Distance between two parallel lines is given by 

c1 = 2 x 11 = 22 and c2 = 15 and A = 8 and B = 6

Now substituting the values we get

 = 7/10

 


Q6. Negation of the statement ∼p→(q∨r) is
Answer : Option A
Explaination / Solution:

rules of negation ∼(p→q)≡p∧∼q Hence ∼p∧(∼q∧∼r)

Q7.  is equal to
Answer : Option D
Explaination / Solution:

elogxdx=elogx1dx=x1dx=log|x|+C
Q8. Correct form of distributive law is
Answer : Option B
Explaination / Solution:

Distributive law is given by :

Q9. The conditional probability of the event E', given that F has occurred is given by
Answer : Option C
Explaination / Solution:

we know that P(S/F) =1 

  P(E U E'|F)=1        since EUE' =S

P(E/F) +P(E'/F) =1          since E and E' are disjoint events

        P(E'/F)  = 1- P(E/F)


Q10.  is
Answer : Option D
Explaination / Solution:

Because both  lies in 3rd quadrant. In 3rd quadrant values of both  sine and cosine functions are negative.