Let us name the players A,Dave,Zack,Paul,E and F
For the first position there are two candidades ( Zack / Paul )
For the second position there is only one candidate i.e. Dave
For the third place there will be 4 candidates (out of Zack and Paul - 1 as one of them is already taken for the first position and A, E and F total-4)
For the fourth place there will be 3 candidates ( out of the four available candidates in the 3rd place, one will be taken up for 3rd place )
For the fifth place there will be 2 candidates
Finally, for the last place there will be only one candidate left.
On multiplying the no. of available cadidates, we get 2 * 1 * 4 * 3 * 2 * 1 = 48 i.e. option (A)
Please mention minor spelling mistakes
For the second question:
Let the no of dotted marbles be 'x' and no of striped marbles be 'y'
then the equation will become as follows
(y+6)/x = 3
and
(x+6)/y = (2/3)
On solving the equations, we will get x = 10 and y = 24
Total balls = 10+24+6 = 40 (option E)
Answer 3 will be ) For the first edge, he can choose 3 paths
For the second edge he can choose 2 paths for each path of its first edge's path
For the third , he is bounded to move on the paths created by the first and the second edges hence 1 path for each path created by the first and the second edge together
It will be multiplication of all the possibilities of the paths of the three edges differently.........
i.e. 3 * 2 * 1 = 6
Ratio is 1:3.....added = 4
1/4(48) = 48/4 = 12
3/4(48) = 144/4 = 36
the 2 groups will be 12 and 36
Roots with imaginary parts always occur in conjugate pairs. Three of the four roots are known and they are all real, which means the fourth root must also be real.
Because we know 3 and -1 (multiplicity 2) are both roots, the last root 
is such that we can write
There are a few ways we can go about finding , but the easiest way would be to consider only the constant term in the expansion of the right hand side. We don't have to actually compute the expansion, because we know by properties of multiplication that the constant term will be 
.
Meanwhile, on the left hand side, we see the constant term is supposed to be 9, which means we have
so the missing root is 3.
Other things we could have tried that spring to mind:
- three rounds of division, dividing the quartic polynomial by 
, then by 
twice, and noting that the remainder upon each division should be 0
- rational root theorem
I don't understand the problem what are you solving for?
