30m^2+27m-20=0. It’s quad

A track star runs two races on a certain day. The probability thathe wins the first race is 0.7, the probability that he wins th

NARA [144]

Answer:

a) 80% probability that he wins at least one race.

b) 30% probability that he wins exactly one race.

c) 20% probability that he wins neither race.

Step-by-step explanation:

We solve this problem building the Venn's diagram of these probabilities.

I am going to say that:

A is the probability that he wins the first race.

B is the probability that he wins the second race.

C is the probability that he does not win any of these races.

We have that:

$A = a + (A \cap B)$

In which a is the probability that he wins the first race but not the second and $A \cap B$ is the probability that he wins both these races.

By the same logic, we have that:

$B = b + (A \cap B)$

The probability that he wins both races is 0.5.

This means that $A \cap B = 0.5$

The probability that he wins the second race is 0.6

This means that $B = 0.6$

$B = b + (A \cap B)$

$0.6 = b + 0.5$

$b = 0.1$

The probability that he wins the first race is 0.7.

This means that $A = 0.6$

$A = a + (A \cap B)$

$0.7 = a + 0.5$

$a = 0.2$

A) he wins at least one race.

This is

$P = a + b + (A \cap B) = 0.2 + 0.1 + 0.5 = 0.8$

There is an 80% probability that he wins at least one race.

B) he wins exactly one race.

This is

$P = a + b = 0.2 + 0.1 = 0.3$

There is a 30% probability that he wins exactly one race.

C) he wins neither race

Either he wins at least one race, or he wins neither. The sum of these probabilities is 100%.

From a), we have that there is an 80% probability that he wins at least one race.

So there is a 100-80 = 20% probability that he wins neither race.

6 0

3 years ago

What is 7.884 rounded to the nearest hundredth

Korvikt [17]

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The Answer is 7.88

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8 0

3 years ago

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A student saves $3 dollars on August 1, $5 on August 2, $7 on August 3, and so on. How much will she save in August 20 ?

Delvig [45]

Here is your answer

Money saved on each successive day is-

$3, &5, $7....

Clearly it forms an AP,

where

a1= 3

common difference, d= 2

n=20

So,

using formula

Tn= a1+(n-1)d

T20= 3+(20-1)2

= 3+ 19×2

= 3+ 38

=41

So, money saved on August 20= $41

Sum of money saved upto August 20 =
n/2 (a1+T20)
= 20/2 (3+41)
= 10× 44
= $440

HOPE IT IS USEFUL

5 0

3 years ago

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Instructions: Find the missing side of the triangle. 24 and 7

ANTONII [103]

We can use the Pythagorean theorem to solve this. The Pythagorean theorem is a^2 + b^2 = c^2. We already have a and b, we need to find c. 24^2 + 7^2 is 625. Then, we need to find the square root of 625 to find c. The answer is 25. x = 25.

5 0

3 years ago

Solve the equation for x and enter your answer in the box below x + 14 =27

Helen [10]

Answer: x = 13

Step-by-step explanation: When solving an equation like this, we are trying to get our variable which is our letter by itself.

So we first want to ask ourselves what is the 14 doing to x. Well, we can see that it's being added to x so to get x by itself, we will do the opposite of addition which is subtraction. So we subtract 14 from both sides of the equation.

The +14 -14 cancels out so we're left with x on the left.

On the right, we must subtract 14 from 27 to get 13.

So we have x = 13 which is the solution to this equation.

3 0

4 years ago

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