The quotient is A coz quotient and multiplication is same thing and when 11 is multiplied in 5 & 12 in 7 it gives the answer
Let's consider an arbitrary 2x2 matrix as an example,

The columns of

are linearly independent if and only if the column vectors

are linearly independent.
This is the case if the only way we can make a linear combination of

reduce to the zero vector is to multiply the vectors by 0; that is,

only by letting

.
A more concrete example: suppose

Here,

and

. Notice that we can get the zero vector by taking

and

:

so the columns of

are not linearly independent, or linearly dependent.
The total number of articles is 14 and only 7 can be published. Since what is asked is the ways to assemble the 7 articles, this is a permutation problem.
14P7 = <span>17297280 ways
If order is not of concern, the problem is just a combination problem
14C7 = </span><span>3432 ways</span><span />
Answer:
Your answers are 1.A 2.T 3.C 4.A