Evaluate the expression: 15(6

For calculate the probability is necessary to identify the total number of ways to color the six number. This can be calculate with the rule of multiplication as:

2*2*2*2*2*2=64

Because we have 2 options to color every number.

For know the number of ways in which the coloring is factorific, first we need to identify the divisors of each number:

1: the divisor is 1

2: The divisors are 2 and 1

3: The divisors are 3 and 1

4: The divisors are 4, 2 and 1

5: The divisors are 5 and 1

6: The divisors are 6, 3 and 1

From these information we analyse that for made a factorific coloring, is necessary that the number 1 is color blue. Additionally if the number 4 is color blue, the number 2 needs to be color blue and if the number 6 is blue, the number 3 needs to be blue.

So, the number of ways in which we can create a factorfic number is determined by the following cases:

The number 2 is blue and the number 3 is blue: In this case we have 1 option for number 1, one for number 2 and 1 for number 3. Taking into account that the number 2 and 3 are blue, if the number 4 and 6 are blue or red doesn't change the fact that the coloring is going to be factorific. So, we have two options for number 3 and 2 options for number 6. Finally the color of the number 5 is independent of the colors of number 2 and 3, so we also have 2 options for coloring number 5 and the coloring is going to be factorific. Then the number of ways for this situation is calculate as:

1 * 1 * 1 * 2 * 2 * 2 = 8

number 1 number 2 number 3 number 4 number 5 number 6

At the same way we can calculate the following cases:

The number 2 is blue and the number 3 is red: If the number 3 is red, the coloring is only going to be factorific is number 6 is red. Then the number of ways for this situation is calculate as:

1 * 1 * 1 * 2 * 2 * 1 = 4

number 1 number 2 number 3 number 4 number 5 number 6

The number 2 is red and the number 3 is red: If the number 2 and 3 are red, the coloring is only going to be factorific is number 4 and 6 are red. Then the number of ways for this situation is calculate as:

1 * 1 * 1 * 1 * 2 * 1 = 2

number 1 number 2 number 3 number 4 number 5 number 6

The number 2 is red and the number 3 is blue: If the number 2 is red, the coloring is only going to be factorific is number 4 is red. Then the number of ways for this situation is calculate as:

1 * 1 * 1 * 1 * 2 * 2 = 4

number 1 number 2 number 3 number 4 number 5 number 6

If we sum all the cases, we obtain 18 ways to make a factorific coloring. So the probability can be calculated as:

$P= \frac{18}{64} = 0.28125$

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3 years ago

Evaluate the expression: 15(6 – 4)