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3 years ago

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A bag contains 4 red marbles and 5 blue marbles. If two marbles are chosen at random, one at a time and without replacement, wha

t is the probability of getting two red marbles?
A. 5/18
B. 40/81
C. 16/81
D. 1/6

2 answers:

kari74 [83]3 years ago

6 0

P(red) 4/9 on the first pull, P(red) 3/8 on the second pull
(4/9)(3/8) = 12/72 = 1/6 Letter D

Gelneren [198K]3 years ago

3 0

Answer:

1/6

Step-by-step explanation:

for the first marble

it might be red or blue

so P (the first red)=4/9

then if the first one is red ,

now we have 3 red and 5 blue ,

the second one might be red again or blue

so P(the second red)= 3/8,

ok

now

P(get two red)=P(the first red) X P(the second red)=4/9x3/8=1/6

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A vertical pole 5ft long casts a shadow of 2ft at the same time a nearby tree casts a shadow of 10ft, how y’all is the tree?

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3 years ago

A point H is 20m away from the foot of a tower on the same horizontal ground. From the point H, the angle of elevation of the po

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Answer:

a. See Attachment 1

b. $PT = 12.3\ m$

c. $HT = 31.1\ m$

d. $OH = 28.4\ m$

Step-by-step explanation:

Calculating PT

To calculate PT, we need to get distance OT and OP

Calculating OT;

We have to consider angle 50, distance OH and distance OT

The relationship between these parameters is;

$tan50 = \frac{OT}{20}$

Multiply both sides by 20

$20 * tan50 = \frac{OT}{20} * 20$

$20 * tan50 = OT$

$20 * 1.1918 = OT$

$23.836 = OT$

$OT = 23.836$

Calculating OP;

We have to consider angle 30, distance OH and distance OP

The relationship between these parameters is;

$tan30 = \frac{OP}{20}$

Multiply both sides by 20

$20 * tan30 = \frac{OP}{20} * 20$

$20 * tan30 = OP$

$20 * 0.5774= OP$

$11.548 = OP$

$OP = 11.548$

$PT = OT - OP$

$PT = 23.836 - 11.548$

$PT = 12.288$

$PT = 12.3\ m$ (Approximated)

--------------------------------------------------------

Calculating the distance between H and the top of the tower

This is represented by HT

HT can be calculated using Pythagoras theorem

$HT^2 = OT^2 + OH^2$

Substitute 20 for OH and $OT = 23.836$

$HT^2 = 20^2 + 23.836^2$

$HT^2 = 400 + 568.154896$

$HT^2 = 968.154896$

Take Square Root of both sides

$HT = \sqrt{968.154896}$

$HT = 31.1\ m$ <em>(Approximated)</em>

--------------------------------------------------------

Calculating the position of H

This is represented by OH

See Attachment 2

We have to consider angle 50, distance OH and distance OT

The relationship between these parameters is;

$tan50 = \frac{OH}{OT}$

Multiply both sides by OT

$OT * tan50 = \frac{OH}{OT} * OT$

$OT * tan50 = {OH$

$OT * 1.1918 = OH$

Substitute $OT = 23.836$

$23.836 * 1.1918 = OH$

$28.4= OH$

$OH = 28.4\ m$ <em> (Approximated)</em>

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3 years ago

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