# A security alarm requires a four-digit code. The code can use the digits 0–9 and the digits cannot be repeated. Which expression can be used to determine the probability of the alarm code beginning with a number greater than 7?

Step-by-step explanation:

We have total of 10 digits from 0 to 9

We need a four digit code and beginning with a number greater than 7

We have 2 choices for number greater than 7

For first digit we have 2 choices

Now, we are left with 9 choices because one is filled and digits should not repeat.

For second digit we have 9 choices

For third digit we will have 8 choices

And for fourth digit we will have 7 choices

Total number of choices are

using

Cancel common terms from numerator and denominator we get:

.

Probability is the chance of an event occurring. The probability of the alarm code beginning with a number greater than 7 is 20%.

What is the Probability?

The probability helps us to know the chances of an event occurring.

We know about the probability, therefore, in order to find the probability of the alarm code beginning with a number greater than 7. We need to find the number of possible choices of an alarm code beginning with a number greater than 7.

As it is given to us that the numbers can not repeat, therefore, the number of possible options between 0-9 reduces, also, in the first place the only numbers that can come is either 8 or 9 so that the code begins with a number greater than 7.

The number of possible options that the code begins with a number 7

The total number of possible codes

Now, the probability of the alarm code beginning with a number greater than 7,

Hence, the probability of the alarm code beginning with a number greater than 7 is 20%.

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## Related Questions

What is 1.833333 repeating as a fraction?

1833/1000 as a top heavy fraction as a mixed fraction it is 1 833/1000

Give one combination of two factors whose product is 0.24, if one of the factors is a whole number greater than 1.

The combination of two factors whose product is 0.24 is 24 x 0.01

The product = 0.24

Convert 0.24 from decimal to fraction

0.24 = 24/100

24/100 can be rewritten as 24 x 1/100

Since 24 is a whole number greater than 1, find the decimal equivalent of 1/100

1/100 = 0.01

0.24  =  24 x 0.01

Therefore, one of the combinations of factors of 0.24 the where one of them is a whole number greater than 1 is 24 x 0.01.

Product of two factors =0.24

It is given that one of the factors is greater than 1.

Because 0.24 when reduced in fraction form , numerator will be divisible by 1,2,3,4,6,8,12,and 24.

So, you can choose from any one of them.

So, let one factor= 2

So, other will be

= 0.24 ÷ 2

=0.12

One Combination is=(2, 0.12)

What equation is equal to 7-4(2x-3)

-8x+19

Or

19-8x

Step-by-step explanation:

To find an equation that is equal to 7-4(2x-3), we can expand the parenthesis using the distributive property.

This implies that:

We group like terms on the right to obtain:

We now combine similar terms on the right to obtain:

Therefore the expression that equals 7-4(2x-3) is -8x+19

Christopher bought a new watch at the store when they were having a 20\%20%20, percent off sale. If the regular price of the watch was \\$48\$48dollar sign, 48, how much did Christopher pay with the discount? \\$\