1
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

$${1 \over {2\,.\,5}} + {1 \over {5\,.\,8}} + {1 \over {8\,.\,11}} + ............. + {1 \over {(3n - 1)(3n + 2)}} = $$

A
$${n \over {6n + 3}}$$
B
$${n \over {6n - 4}}$$
C
$${{n + 1} \over {6n + 4}}$$
D
$${n \over {6n + 4}}$$
2
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

The ninth term of the expansion $${\left( {3x - {1 \over {2x}}} \right)^8}$$ is

A
$${{ - 1} \over {512{x^9}}}$$
B
$${1 \over {512{x^9}}}$$
C
$${1 \over {256.\,{x^8}}}$$
D
$${{ - 1} \over {256.\,{x^8}}}$$
3
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

If $$A = \left[ {\matrix{ 1 & { - 1} & 1 \cr 2 & 1 & { - 3} \cr 1 & 1 & 1 \cr } } \right],10B = \left[ {\matrix{ 4 & 2 & 2 \cr { - 5} & 0 & \alpha \cr 1 & { - 2} & 3 \cr } } \right]$$ and B is the inverse of A, then the value of $$\alpha$$ is

A
0
B
2
C
4
D
5
4
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

If $$A = \left[ {\matrix{ 0 & x & {16} \cr x & 5 & 7 \cr 0 & 9 & x \cr } } \right]$$ is singular, then the possible values of x are

A
$$0,1,-1$$
B
$$0,+12,-12$$
C
$$0,5,-5$$
D
$$0,4,-4$$
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12