) In New South Wales, each adult on the electoral roll has a 10% of being called up for jury duty in any year. A company has 25 employees on the electoral roll. i) What is the probability that more than two employees are called up for jury duty in any year

The probability is

Step-by-step explanation:

We know that in New South Wales, each adult on the electoral roll has a 10 % of being called up for jury duty in any year.

We can write this probability as :

We also know that a company has 25 employees on the electoral roll.

We can write this as :

Now we can assume that this is a Bernoulli process in which the election of a random adult is independent and also the probability of being called remains the same

We also define the Binomial random variable in the Bernoulli process that counts the number of successes given that we set a number of individual experiments.

In this exercise, we will call a ''success'' when an adult is being called up for jury duty. We also set the number of experiments to (being this number the total employees of the company).

We define the random variable as :

'' Number of employees being called up for jury duty in any year from the total of 25 employees ''

⇒ ~ Bi ( n , p ) ⇒ ~ Bi ( 25 , 0.1 )

This means that can be modeled as a Binomial random variable with parameters ''n'' and ''p''.

We can calculate probabilities using the following equation :

Where is the combinatorial number define as :

We want to calculate ⇒

  ⇒

 We found out that the probability is

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

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x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

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x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

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x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!

the answer is 3/5

step-by-step explanation:

first divide 24 divided by 8 because that is the least common multiple

then divide 40 by 8

then you will get 3/5.