Mathematics - Online Test

Q1. Each diagonal element of a skew-symmetric matrix is
Answer : Option A
Explaination / Solution:

The diagonal elements of a skew-symmetric is zero.

Q2. Different calendars for the month of February are made so as to serve for all the coming years. The number of such calendars is
Answer : Option C
Explaination / Solution:

The month of February  has either 28 days (non-Leap Year)  or 29 days(Leap Year).

Thus there are 2 possibility  for the number of days in February.

Also the first day of the month of February can be any of the 7 days in a week.

So total number of February calendars = 2 * 7 =14


Q3. Two lines  are coplanar if
Answer : Option D
Explaination / Solution:

In vector form:
Two lines  are coplanar if (
.
Q4. To form a differential equation from a given function
Answer : Option A
Explaination / Solution:

We shall differentiate the function equal to the number of arbitrary constant so that we get equations equal to arbitrary constant and then eliminate them to form a differential equation

Q5.

If α is a complex a number such that  then  is


Answer : Option C
Explaination / Solution:



Q6.  is
Answer : Option D
Explaination / Solution:



Q7. Which set is the subset of all given sets ?
Answer : Option A
Explaination / Solution:

{ } denoted as null set. and Null set is subset of all sets.

Q8.  is equal to
Answer : Option B
Explaination / Solution:



Q9. A factory manufactures two types of screws, A and B. Each type of screw requires the use of two machines, an automatic and a hand operated. It takes 4 minutes on the automatic and 6 minutes on hand operated machines tomanufacture a package of screws A, while it takes 6 minutes on automatic and 3 minutes on the hand operated machines to manufacture a package of screws B. Each machine is available for at the most 4 hours on any day. The manufacturer can sell a package of screws A at a profit of Rs 7 and screws B at a profit of Rs 10. Assuming that he can sell all the screws he manufactures, how many packages of each type should the factory owner produce in a day in order to maximize his profit? Determine the maximum profit.
Answer : Option B
Explaination / Solution:

Let number of packages of screws A produced = x
And number of packages of screws B produced = y
Therefore , the above L.P.P. is given as :
Maximise , Z = 7x +10y , subject to the constraints : 4x +6y ≤ 240 and. 6x +3y ≤ 240 i.e. 2x +3y ≤ 120 and 2x +y ≤ 80 , x, y ≥ 0.

Corner points

Z =7 x +10 y

O( 0 , 0 )

0

D(40,0 )    

280

A(0,40)

400

B(30,20)

410…………………(Max.)

Here Z = 410 is maximum.
i.e 30 packages of screws A and 20 packages of screws B; Maximum profit = Rs 410.


Q10. Solve the system of inequalitie: 
Answer : Option D
Explaination / Solution: