Mathematics - Online Test
Q1. 5 persons board a lift on the ground floor of an 8 storey building. In how many ways can they leave the lift?
Answer : Option A
Explaination / Solution:
Since they are boarding from ground floor and we are considering the number of ways they leave the lift ,we can consider there are 7 floor sas we exclude the ground floor)
As each of the 5 persons can leave the lift in 7 ways, required number of ways= 75
Q2. If and are the direction cosines of two lines; and is the acute angle between the two lines; then
Answer : Option A
Explaination / Solution:
If and are the direction cosines of two lines; and is the acute angle between the two lines; then the cosine of the angle between these two lines is given by : .
Q3. The area of a triangle is and its perimeter is 8 cm. The radius of its inscribed circle is
Answer : Option A
Explaination / Solution:
Q4.
The area bounded by y = 2cosx , x = 0 to x =2π and the axis of x in square units is
Answer : Option C
Explaination / Solution:
$= = == 2
Therefore , total area from x= 0 to x = 2 is 4 X 2= 8 sq. units.
Therefore , total area from x= 0 to x = 2 is 4 X 2= 8 sq. units.
Q5. The lines, which do not lie in the same plane, are called ?
Answer : Option C
Explaination / Solution:
Lines which lie in same plane can be parallel, coincident or intersecting.
Skew lines are those lines which lie in different planes and never meet to each other
Q6. If a square matrix A has two identical rows or columns , then det.A is :
Answer : Option C
Explaination / Solution:
If two rows or column of a matrix are identical then determinant of such a matrix is zero.
Q7. The function f (x) = m x + c where m, c are constants, is a strict decreasing function for all x∈R , if
Answer : Option D
Explaination / Solution:
f ( x) = mx + c is strict decreasing on R
if f ‘ ( x) < 0 i.e. if m < 0 .
Q8. Let U = { 1,2,3,4,5,6,7,8,9,10 } , A = { 1,2,5 } , B = { 6,7 }. Then A∩B′ is
Answer : Option A
Explaination / Solution:
Q9. With initial condition
x(1) = 0.5, the solution of the differential equation 
is
is
Answer : Option D
Explaination / Solution:
Q10. Multiplicative inverse of the non zero complex number x + iy (x,y∈R,)
Answer : Option D
Explaination / Solution:
Multiplicative inverse of the complex number x + iy =
