Discrete Mathematics Answers

find the coefficient of x^3 y^3 in the expansion of (x+y)^n

Use a truth table to determine whether the argument given below is valid:
If it is a wild animal, it is dangerous. If it is dangerous, it will hurt
you. However, it is not dangerous. Therefore, it is not a wild animal.

Let A={x|x is even},B= 1 ,2,3,......,99,100},C={3,5,7,9} D={101,102} and E={101,103,105}.which of these sets can equal S if SA and S and B are disjoint? a.)A,b.)B,c.)C,d.)D,e.)E

Let a={2,{4,5},4}.which statement is correct? A.) 5 is an element of b,B.) {5} is an element of A C.) {4,5} is an element in A D.) {5} is a subset of A

In a primary school , the parents were asked about the number of hours they spend per day in helping their chaildren do their homework . there were 90 parents who helped for 1 and a half or half hour.50% did not help , 20% helped more 1 and a half hour and 30% helped for half hour to 1 and half hour .
how many parents were surveyed ?
how many said they did not help ?
how many said they did not helped for more than 1 and a half ?

In how many ways can one distribute ten distinct prizes among four students with exactly two students getting nothing?

How many ways have at least two students getting nothing?

Let T: R3→R3 be a L.T. and defined by T(a,b,c)=(a-b,b-c,c-a).Find the matrix with respect to basis (v1v2v3)where v1=(1,0,1),v2=(0,1,1),v3=(1,1,0) is this matrix invertible if so find inverse corresponding to formula for T-1.

which mathematical sign is to be put in the 4 and 5 so that the answer is more than 4 but less than 5.

A man standing at a point P on a flat plane starts walking. At eacj step, he walks exactly 1 foot in one of the directions N,S,E or W. Suppose that after 6 steps he comes back to P, then no. of disctinct paths he can take is ?

what is discret mathimatics?