How many ways can a person toss a coin 13 times so that the number of tails is between 7 and 9 inclusive

3718 ways

Step-by-step explanation:

How many ways can a person toss a coin 13 times so that the number of tails is between 7 and 9 inclusive

Probability is the likelihood for an event to occur  or not

The formula for a combination is:

n choose r = n! / (r! x (n-r)!)  

n=13

r=7 to 9

We are going to add up the cases for 7 through 9:

++

++

1716+1287+715

3718 ways

find the magnitude of the trig term  

csc

(

x

)

−

1

by taking the absolute value of the coefficient.

1

find the lower bound of the range.

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y

=

−

2

find the upper bound of the range.

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y

=

0

the range is  

y

≤

−

2

or  

y

≥

0

.

(

−

∞

,

−

2

]

∪

[

0

,

∞

)

{

y

|

y

≤

−

2

,

y

≥

0

}

step-by-step explanation: