8 total pens....4 are black
first pick, probability of being black is 4/8
2nd pick. without replacing, probability is 3/7
probability of a black pen picked first and then another black pen picked again is : 4/8 * 3/7 = 12/56 = 0.21
Answer:
600
Step-by-step explanation:
Let's consider this question using algebra.
Imagine the number of bricks in the original pile is .
We are told that of the bricks are used for a project, meaning that has been used, leaving us with as our remainder.
Then, we are told that of the remainder are used to leave us with 50 bricks. This means that of the remainder is left, and this is equal to 50 bricks. This means that the remainder's original amount is equal to 150, because we are told that of the remainder is equal to 50.
So, we know that the remainder is 150, and we also know that the remainder is . Let's now use these to form an equation.
Because we know that a quarter of the original amount of bricks is equal to 150, we can multiply both sides of the equation by 4 to get the original amount of bricks in the pile.
So, there were 600 bricks in the original pile.
The value of cos(L) in the triangle is Five-thirteenths
<h3>What are right triangles?</h3>
Right triangles are triangles whose one of its angle has a measure of 90 degrees
<h3>How to determine the value of cos(L)?</h3>
The value of a cosine function is calculated as:
cos(L) = Adjacent/Hypotenuse
The hypotenuse is calculated as
Hypotenuse^2 = Opposite^2 + Adjacent^2
So, we have:
Hypotenuse^2 = 12^2 + 5^2
Evaluate
Hypotenuse^2 = 169
Take the square root of both sides
Hypotenuse = 13
So, we have
Adjacent = 5
Hypotenuse = 13
Recall that
cos(L) = Adjacent/Hypotenuse
This gives
cos(L) = 5/13
Hence, the value of cos(L) in the triangle is Five-thirteenths
Read more about right triangles at:
brainly.com/question/2437195
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