12.5% as a fraction in simplest form

You are given the information that P(A) = 0.30 and P(B) = 0.40.

Ad libitum [116K]

Answer:

1.B. No. You need to know the value of P(A and B). 2.C. Yes P(A and B) =0, so P(A or B) = P(A) + P(B).

Step-by-step explanation:

We can solve this question considering the following:

For two mutually exclusive events:

$\\ A_{1}\;and\;A_{2}$

$\\ P(A_{1} or A_{2}) = P(A_{1}) + P(A_{2})$ (1)

An extension of the former expression is:

$\\ P(A_{1} or A_{2}) = P(A_{1}) + P(A_{2}) - P(A_{1} and A_{2})$ (2)

In mutually exclusive events, P(A and B) = 0, that is, the events are independent one of the other, and we know the probability that both events happen at the same time is zero (P(A and B) = 0). There are some other cases in which if event A happens, event B too, so they are not mutually exclusive because P(A and B) is some number different from zero. Notice the difference between OR and AND. The latter implies that both events happen at the same time.

In other words, notice that the formula (2) provides an extension of formula (1) for those events that are not mutually exclusive, that is, there are some cases in which the events share the same probabilities in a way that these probabilities must be subtracted from the total, so those probabilities in common do not "inflate" the actual probability.

For instance, imagine a person going to a gas station and ask for checking both a tire and lube oil of his/her car. The probability for checking a tire is P(A)=0.16, for checking lube oil is P(B)=0.30, and for both P(A and B) = 0.07.

The number 0.07 represents the probability that both events occur at the same time, so the probability that this person ask for checking a tire or the lube oil of his/her car is:

P(A or B) = 0.16 + 0.30 - 0.07 = 0.39.

That is why we cannot simply add some given probabilities without acknowledging if the events are or not mutually exclusive, whereas we can certainly add the probabilities in question when we know that both probabilities are mutually exclusive since P(A and B) = 0.

In conclusion, knowing the events are mutually exclusive does provide extra information and we can proceed to simply add the probabilities of either event; thus, the answers are those in which we need to previously know the value of P(A and B).

7 0

3 years ago

The line AB has midpoint (2,5). A has coordinates (1, 2). Find the coordinates of B.

Gekata [30.6K]

Answer:

$X_m = \frac{A_x +B_x}{2}= \frac{1+B_x}{2}= 2$

And we can solve for $B_x$ and we got:

$1+B_x = 4$

$B_x = 3$

$Y_m = \frac{A_y +B_y}{2}= \frac{2+B_y}{2}= 5$

And we can solve for $B_x$ and we got:

$2+B_y = 10$

$B_y = 8$

So then the coordinates for B are (3,8)

Step-by-step explanation:

For this case we know that the midpoint for the segment AB is (2,5)

And we know that the coordinates of A are (1,2)

We know that for a given segment the formulas in order to find the midpoint are given by:

$X_m = \frac{A_x +B_x}{2}= \frac{1+B_x}{2}= 2$

And we can solve for $B_x$ and we got:

$1+B_x = 4$

$B_x = 3$

$Y_m = \frac{A_y +B_y}{2}= \frac{2+B_y}{2}= 5$

And we can solve for $B_x$ and we got:

$2+B_y = 10$

$B_y = 8$

So then the coordinates for B are (3,8)

7 0

3 years ago

3x-4 or = to 7 plz help

lisabon 2012 [21]

Answer:

3 + 4 = 7 which is true.

Step-by-step explanation:

Whenever you have an equation with a plain variable (that is, no exponent included), there is only one number that will work when substituted for x.

To solve it, you have to "undo" what is done to the variable. You also go in the reverse order of operations, so you do the addition/subtract first, then multiplication/division.

You also have to do the same to both sides, kind of like keeping a balance scale in balance.

In this case, we subtract 4 from both sides first:

3x + 4 -4 = 7 - 4

The + 4 - 4 cancel each other out, so you get:

3x = 3

3x means "3 times x" so you divide by 3 to undo it. I will use the / to indicate division:

3x / 3 = 3 /3

so 1x = 1.

Since 1x is "1 times x" it is the same as x by itself, so:

x=1

AND, if we substitute 1 back into the original equation (the asterisk stands for multiply):

3 * 1 + 4 = 7

3 * 1 is 3, so:

3 + 4 = 7 which is true.

1 is the only number that works.

Hope this helped.

3 0

3 years ago

Read 2 more answers

Which pair of numbers is relatively prime?

stiv31 [10]

The answer tour question is D

3 0

3 years ago

Read 2 more answers

2×+3(×-4)=8 what the answer to this problem

Contact [7]

Answer:

4

Step-by-step explanation:

2x+3(x-4)=8

2x+3x-12=8

5x-12=8

5x-12+12=8+12

5x=20

5x/5=20/5

x=4

3 0

3 years ago

Read 2 more answers