Mathematics - Online Test

Q1. Reshma wishes to mix two types of food P and Q in such a way that the vitamin contents of the mixture contain at least 8 units of vitamin A and 11 units of vitamin B. Food P costs Rs 60/kg and Food Q costs Rs 80/kg. Food P contains 3 units/kg of Vitamin A and 5 units / kg of Vitamin B while food Q contains 4 units/kg of Vitamin A and 2 units/kg of vitamin B. Determine the minimum cost of the mixture.
Answer : Option B
Explaination / Solution:

Let number of food type P = x
And number of units of food type Q = y
Therefore , the above L.P.P. is given as :
Minimise , Z = 60x +80y , subject to the constraints : 3 x + 4y ≥ 8, 5x + 2y ≥ 11, x,y ≥ 0.

The corner points can be obtained by drawing the lines 3x+4y=8 and 5x+2y=11 graphically.

The points so obtained are (8/3,0), (2,1/2), (0,11/2)

Corner points

Z =  - x + 2y

D(8/3,0 )   

160………………….(Min.)

A(2,1/2)

160………………(Min.)

B(0,11/2)

440

Here Z = 160 is minimum. i.e. Minimum cost = Rs 160 at all points lying on segment joining (83,0)and(2,12) .


Q2. Solve the system of inequalities (x + 5 ) − 7 ( x − 2 ) ≥ 4x + 9 , 2 ( x − 3 ) − 7 ( x + 5 ) ≤ 3x − 9
Answer : Option A
Explaination / Solution:


Hence the solution set is 

Which means 


Q3. The 20th term of the series 2×4+4×6+6×8+... is
Answer : Option C
Explaination / Solution:

here,


Q4. The median of the data 13,14,16,18,20,22 is
Answer : Option C
Explaination / Solution:



Q5.

The area bounded by the curves  is given by


Answer : Option A
Explaination / Solution:

Both  and  are symmetric about y – axis and on solving them we get :


required area :
 = 

Q6. A relation R on a set A is called an empty relation if
Answer : Option C
Explaination / Solution:

For any set A ,an empty relation may be defined on A as: there is no element exists in the relation set which satisfies the relation for a given set A i.e. let A={1,2,3,4,5} and R={(a,b): a,b ∈A and a+b= 10},so we get R={ } which is an empty relation.

Q7.
Answer : Option A
Explaination / Solution:



Q8. The lines x + 2y – 3 = 0, 2x + y – 3 = 0 and the line l are concurrent . If the line I passes through the origin, then its equation is
Answer : Option C
Explaination / Solution:

Equation of a line passing through the intersection of two lies is given by ax1 +by1 +c1 + k(ax2 +by2 +c2) = 0

Hence x+2y-3 + k(2x+y-3) = 0

Since it passes through (0,0)

-3 -3k = 0

This implies k = -1

Sustituting for k we get,

x+2y-3 +(-1)(2x+y-3) = 0

-x +y =0 or x - y = 0


Q9. Which of the following is always true ?
Answer : Option A
Explaination / Solution:

        Since 


Q10. x dx is equal to
Answer : Option D
Explaination / Solution: