Mathematics - Online Test

Q1. The coefficient of  in the expansion of   is
Answer : Option A
Explaination / Solution:



Q2. Let A and B be subsets of a set X , Then which of the following is correct
Answer : Option A
Explaination / Solution:



Q3. The normal to the curve x = a (cosθ+θsinθ),y = a (sinθ−θcosθ)at any point θ is such that
Answer : Option A
Explaination / Solution:

Equation of normal at θisxcosθ+ysinθ−a=0.So,normal is at a fixed distance a from the origin.

Q4. The area of the smaller portion of the circle cut off by the line x = 1 is
Answer : Option A
Explaination / Solution:



Q5.  is equal to
Answer : Option D
Explaination / Solution:



Q6. Minimize Z = 5x + 10 y subject to x + 2y ≤ 120, x + y ≥ 60, x – 2y ≥ 0, x, y ≥ 0
Answer : Option D
Explaination / Solution:

Objective function is Z = 5x + 10 y ……………………(1).
The given constraints are : x + 2y ≤ 120, x + y ≥ 60, x – 2y ≥ 0, x, y ≥ 0 .

The corner points are obtained by drawing the lines x+2y =120, x+y = 60 and x-2y = 0. The points so obtained are (60,30),(120,0), (60,0) and (40,20)

Corner points

Z = 5x + 10y

D(60 ,30 )

600

A(120,0)

600

B(60,0)

300……………………..(Min.)

C(40,20)

400

Here , Z = 300 is minimum at ( 60, 0 ).


Q7. Solve the system of inequalities 2x + 5 ≤ 0 , x − 3 ≤ 0
Answer : Option D
Explaination / Solution:



Q8. The ratio of the  to the ( n –1)th mean between 1 and 31, when n arithmetic means are inserted between them, is 5 : 9. The value of n is
Answer : Option B
Explaination / Solution:



Q9. If the mean of the first n odd natural numbers be n itself, then n is equal to
Answer : Option C
Explaination / Solution:


here, n can be any natural number


Q10. Let R = {(1, 3), (4, 2), (2, 4), (2, 3), (3, 1),(3,2)} be a relations on the set A = {1, 2, 3, 4}. The relation R is
Answer : Option C
Explaination / Solution:

R is said to be symmetric if (a,b)∈R⇒(b,a)∈R ,here (1,3)∈R⇒(3,1)∈R etc.