Question

help???

Answer 1

Barbara draws pens randomly from a box containing 5 pens of the same shape and size. There is 1 green pen, 3 red pens, and 1 blue pen. She draws 1 red pen and then another red pen without replacing the first one. Find the probability of drawing 1 red pen followed by another red pen, and show the equation used.

Answer 2

@Michele_Laino help???????

Answer 3

@Michele_Laino i need help????

Answer 4

@Michele_Laino

Answer 5

sorry for tagging you so much

Answer 6

no worries :)

Answer 7

can you help me?

Answer 8

yes! I try!

Answer 9

Barbara draws pens randomly from a box containing 5 pens of the same shape and size. There is 1 green pen, 3 red pens, and 1 blue pen. She draws 1 red pen and then another red pen without replacing the first one. Find the probability of drawing 1 red pen followed by another red pen, and show the equation used.

Answer 10

the probability to draw a red pen is given by the subsequent ratio:
\[robability = \frac{{favorable\;cases}}{{possible\;cases}}\]

Answer 11

\[probability = \frac{{favorable\;cases}}{{possible\;cases}}\]

Answer 12

so what do i do?

Answer 13

now, the favorable cases is given by the number of red pens, namely we have 23 red pens, so, favorable cases = 3. Whereas the possible cases is given by the total number of pens, so, possible cases = 5

Answer 14

oops..we have 3 red pens

Answer 15

then our ratio is:
\[probability = \frac{{favorable\;cases}}{{possible\;cases}} = \frac{3}{5} = ...?\]

Answer 16

you mean as percent?

Answer 17

yes!

Answer 18

6 percent

Answer 19

I think:
(3/5)*100=60%

Answer 20

so that is the answer

Answer 21

no, we have to continue. that's the probability to get a red pen after the first draw.

Answer 22

oh ok

Answer 23

whats next

Answer 24

now when Barbara draws a second red pen, we have to apply the formula above. Nevertheless, the possible cases are 4, since we have only 4 pens.
So our probability, is:
\[probability = \frac{{favorable\;cases}}{{possible\;cases}} = \frac{2}{4} = ...?\]

Answer 25

the favorable cases are 2, since before the second draw we have 2 red pens

Answer 26

so 50%

Answer 27

ok!

Answer 28

now the requested probability, is given by the product of those probabilities, namely:
\[requested\;probability = 60\% \times 50\% = ...?\]

Answer 29

3,000%

Answer 30

or:
\[\begin{gathered}
requested\;probability = 60\% \times 50\% = \hfill \\
\hfill \\
= \frac{{60}}{{100}} \times \frac{{50}}{{100}} = ...? \hfill \\
\end{gathered} \]

Answer 31

3,000% is too high

Answer 32

but 60 times 50 equals 3,000

Answer 33

yes! Then you have to divide that number by 10,000

Answer 34

hint:
\[\frac{{60}}{{100}} \times \frac{{50}}{{100}} = \frac{{60 \times 50}}{{100 \times 100}} = \frac{{3000}}{{10000}} = ...?\]

Answer 35

0.3 = 30%

Answer 36

that's right!

Answer 37

so is that the answer

Answer 38

30%

Answer 39

yes!

Answer 40

so how would i say that as my answer

Answer 41

i need help with three more questions if that is ok??

Answer 42

since we have multiplied the single probabilities, then we have applied this equation:
\[requested\;probability = p1 \times p2\]
where
p_1=60%
and
p_2=50%

Answer 43

that's your answer

Answer 44

what is my answer

Answer 45

30%

Answer 46

your answer is:
\[requested\;probability = 30\% \]
formula applied:
\[requested\;probability = {p_1} \times {p_2},\quad {p_1} = 60\% ,\quad {p_2} = 50\% \]

Answer 47

ok next question

Answer 48

Minni is arranging 3 different music CDs in a row on a shelf. Create a sample space for the arrangement of a jazz CD (J), a pop CD (P), and a rock CD (R).

Answer 49

a possible arrangement of thos CDs can be this: