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3 years ago

In how many ways can a president and a vice president be randomly selected from a class of 20 students?

Mathematics

1 answer:

SpyIntel [72]3 years ago

7 0

Answer:

n how many ways can a president, vice president, and a secretary be chosen? It is 12X11X10. Permutation of n things taken r at a time: nPr=n!/(n-r)! 12P3=12*11*10*9!/9!= 12*11*10=1320 ways.

Step-by-step explanation:

You might be interested in

For what value of k is there one solution to the given quadratic equation (k+1)x²+4kx+2=0.

andriy [413]

Answer:

If $k = 1$ or $k = -\frac{1}{2}$ , there is only one solution to the given quadratic equation.

Step-by-step explanation:

Given a second order polynomial expressed by the following equation:

$ax^{2} + bx + c, a\neq0$

This polynomial has roots $x_{1}, x_{2}$ such that $ax^{2} + bx + c = (x - x_{1})*(x - x_{2})$ , given by the following formulas:

$x_{1} = \frac{-b + \sqrt{\bigtriangleup}}{2*a}$

$x_{2} = \frac{-b - \sqrt{\bigtriangleup}}{2*a}$

$\bigtriangleup = b^{2} - 4ac$

The signal of $\bigtriangleup$ determines how many real roots an equation has:

$\bigtriangleup > 0$ : Two real and different solutions

$\bigtriangleup = 0$ : One real solution

$\bigtriangleup < 0$ : No real solutions

In this problem, we have the following second order polynomial:

$(k+1)x^{2} + 4kx + 2 = 0$ .

This means that $a = k+1; b = 4k; c = 2$

It has one solution if

$\bigtriangleup = 0$

$b^{2} - 4ac = 0$

$16k^{2} -8(k+1) = 0$

$16k^{2} - 8k - 8 = 0$

We can simplify by 8

$2k^{2} - k - 1 = 0$

The solution is:

$k = 1$ or $k = -\frac{1}{2}$

So, if $k = 1$ or $k = -\frac{1}{2}$ , there is only one solution to the given quadratic equation.

4 0

3 years ago

What is the slope of the line graphed (3,9) and (0,-3)

grigory [225]

Answer:

Step-by-step explanation:

9 - (-3) = 12/3= 4

3-0

3 0

3 years ago

The area of each square is 16 square units find the perimeter of a figure

vivado [14]

area=length*width

4*4=16

4+4+4+4=16

the perimeter is also 16

6 0

3 years ago

How do you know am equation has no solution?

Natasha2012 [34]

If u work it out and both sides don't equal, then there is no solution.
Example :
2x + 4 = 2x + 6
2x - 2x = 6 - 4
0 = 2....this is incorrect...therefore, there is no solution

7 0

3 years ago

Read 2 more answers

4(x+3)=3(3x-1)

zhuklara [117]

24=26 is the answer... want mhe 2 show you?

5 0

3 years ago