Mathematics - Online Test

Q1.

The normal to the curve 2 y = 3 – at (1, 1) is


Answer : Option C
Explaination / Solution:



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



Q3. Minimize Z = x + 2y subject to x + 2y ≥ 100, 2x – y ≤ 0, 2x + y ≤ 200; x, y ≥ 0.
Answer : Option B
Explaination / Solution:

Objective function is Z = x + 2 y ……………………(1).
The given constraints are : x + 2y ≥ 100, 2x – y ≤ 0, 2x + y ≤ 200; x, y ≥ 0.

The corner points are obtained by drawing the lines x+2y=100, 2x-y=0 and 2x+y=200.

The points so obtained are (0,50),(20,40), (50,100) and (0,200)

Corner points

Z = x + 2y

D(0 ,50 )

100……………..(Min.)

A(20,40)

100……………………..(Min.)

B(50,100)

250

C(0,200)

400

Here , Z = 100 is minimum at ( 0, 50) and ( 20 ,40).
Minimum Z = 100 at all the points on the line segment joining the points (0, 50) and (20, 40).


Q4. Solve the system of inequalities x − 2 > 0 , 3x < 18
Answer : Option C
Explaination / Solution:



Q5. The sum of first n terms of the series 1 – 1 + 1 – 1 + … is
Answer : Option C
Explaination / Solution:



Q6. The area of the smaller segment cut off from the circle  by x = 1 is
Answer : Option C
Explaination / Solution:



Q7. The mean of the first n terms of the A.P. (a + d ) + ( a + 3d ) + ( a + 5d ) +………..is
Answer : Option B
Explaination / Solution:



Q8. In Z , the set of integers , inverse of – 7 , w.r.t. ‘ * ‘ defined by a*b = a +b + 7 for all a,b∈Z ,is
Answer : Option B
Explaination / Solution:

If ‘ e ‘ is the identity ,then a*e = a ⇒a + e + 7 = a ⇒ e = - 7 . Also,inverse of e is e itself. Hence , inverse of -7 is -7.

Q9.   then D is equal to
Answer : Option D
Explaination / Solution:




Q10. The line x + y – 6 = 0 is the right bisector of the segment [PQ]. If P is the point ( 4, 3 ) , then the point Q is
Answer : Option B
Explaination / Solution:

Equation of the line which is perpendicular to the given line x + y = 6 is x - y + k = 0

Since it passes through the point (4,3)

4 - 3 + k = 0

Therefore k = -1

Hence the equation of the line segment PQ is x - y - 1 = 0

On solving these two lines we get x = 7/2 and y = 5/2

This point of intersection is the midpoint of the line segement PQ

That is  = 7/2 Hence x = 3

Similarly  = 5/2. Hence y = 2

Hence the coordiates of the point Q is (3,2)