Mathematics - Online Test

Q1. If A = { 0,1,5,4,7 }. Then the total number subsets of A are
Answer : Option D
Explaination / Solution:

in any set having n elements then Total no of subsets=2n

so total subset = 25=32


Q2.   is equal to
Answer : Option D
Explaination / Solution:



Q3. A factory makes tennis rackets and cricket bats. A tennis racket takes 1.5 hours of machine time and 3 hours of craftman’s time in its making while a cricket bat takes 3 hour of machine time and 1 hour of craftman’s time. In a day, the factory has the availability of not more than 42 hours of machine time and 24 hours of craftsman’s time. If the profit on a racket and on a bat is Rs 20 and Rs 10 respectively, find the maximum profit of the factory when it works at full capacity?
Answer : Option A
Explaination / Solution:

Let number of rackets made = x
And number of bats made = y
Therefore , the above L.P.P. is given as :
Maximise , Z = x +y , subject to the constraints : 1.5x +3y ≤ 42 and. 3x +y ≤ 24, i.e.0.5x + y ≤ 14 i.e. x +2y ≤ 28 and 3x +y ≤ 24 , x, y ≥ 0.

Corner points

Z =  x + y

O( 0 , 0 )

0

D(0,14 )    

14

A(8,0)

8

B(4,12)

16…………………(Max.)

Here Z = 16 is maximum. i.e Maximum number of rackets = 4 and number of bats = 12.
Here , profit function is P = 20x + 10y
Profit is maximum at x = 4 and y = 12 .
Therefore , maximum profit = 20(4) + 10 ( 12) = 200.i.e. Rs.200.


Q4. Solve the system of inequalities − 2 ≤ 6x − 1 < 2
Answer : Option D
Explaination / Solution:



Q5. The line touches the curve at the point
Answer : Option C
Explaination / Solution:



Q6. The sum of all 2-digited numbers which leave remainder 1 when divided by 3 is
Answer : Option D
Explaination / Solution:



Q7. If the two lines of regression are y = 3x – 5 and y = 2x – 4 , then ρ(X,Y) is equal to
Answer : Option A
Explaination / Solution:

let us assume that y = 3x – 5 and y = 2x – 4 are lines of regression of x on y and y on x respectively,therefore



but sign of ρ is same as  and 

therefore 


Q8. The positive value of the parameter a for which the area of the figure bounded by y = sin ax , y = 0 , x =  is 3 is equal to
Answer : Option B
Explaination / Solution:



Q9. Let A be the set of all students of a boys school. The relation R on A is given by R = {(a, b) : a is sister of b} is
Answer : Option A
Explaination / Solution:

Because , the relation is defined over the set A be the set of all students of a boys school.

Q10. If the entries in a 3 x 3 determinant are either 0 or 1 , then the greatest value of this determinant is :
Answer : Option C
Explaination / Solution:

Greatest value = 2 .