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3 years ago

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10 of 16 students in Bob's Class are girls. His teacher selected two helpers by randomly drawing names. he drew a boy's name fir

st and then a girl's name. Bob thinks that the probability of this happening is 15 / 64 is he correct? If not explain his error

1 answer:

ehidna [41]3 years ago

7 0

<h2>He is right...I guess? maybe maybe not?</h2>

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NASA launches a rocket at t = 0 seconds. Its height, in meters above sea-level, as a function of time is given by h ( t ) = − 4.

Oliga [24]

Answer:

$\displaystyle 1)48.2 \: \: \text{sec}$

$\rm \displaystyle 2)3021.6 \: m$

Step-by-step explanation:

<h3>Question-1:</h3>

so when <u>flash down</u><u> </u>occurs the rocket will be in the ground in other words the elevation(height) from ground level will be 0 therefore,

to figure out the time of flash down we can set h(t) to 0 by doing so we obtain:

$\displaystyle - 4.9 {t}^{2} + 229t + 346 = 0$

to solve the equation can consider the quadratic formula given by

$\displaystyle x = \frac{ - b \pm \sqrt{ {b}^{2} - 4 ac} }{2a}$

so let our a,b and c be -4.9,229 and 346 Thus substitute:

$\rm\displaystyle t = \frac{ - (229) \pm \sqrt{ {229}^{2} - 4.( - 4.9)(346)} }{2.( - 4.9)}$

remove parentheses:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ {229}^{2} - 4.( - 4.9)(346)} }{2.( - 4.9)}$

simplify square:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ 52441- 4( - 4.9)(346)} }{2.( - 4.9)}$

simplify multiplication:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ 52441- 6781.6} }{ - 9.8}$

simplify Substraction:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ 45659.4} }{ - 9.8}$

by simplifying we acquire:

$\displaystyle t = 48.2 \: \: \: \text{and} \quad - 1.5$

since time can't be negative

$\displaystyle t = 48.2$

hence,

at <u>4</u><u>8</u><u>.</u><u>2</u><u> </u>seconds splashdown occurs

<h3>Question-2:</h3>

to figure out the maximum height we have to figure out the maximum Time first in that case the following formula can be considered

$\displaystyle x _{ \text{max}} = \frac{ - b}{2a}$

let a and b be -4.9 and 229 respectively thus substitute:

$\displaystyle t _{ \text{max}} = \frac{ - 229}{2( - 4.9)}$

simplify which yields:

$\displaystyle t _{ \text{max}} = 23.4$

now plug in the maximum t to the function:

$\rm \displaystyle h(23.4)- 4.9 {(23.4)}^{2} + 229(23.4)+ 346$

simplify:

$\rm \displaystyle h(23.4) = 3021.6$

hence,

about <u>3</u><u>0</u><u>2</u><u>1</u><u>.</u><u>6</u><u> </u>meters high above sea-level the rocket gets at its peak?

5 0

2 years ago

Which of the numbered stones shown cannot be mapped to another with a rigid motion?

Andreas93 [3]

Answer:

7,8,11,12,13,14

8 0

2 years ago

I need help on 17 and 23 pls

ludmilkaskok [199]

Question # 17 Solution

Answer:

$x_{1}= \frac{mx_{2}-y_{2}+y_{1}}{m}$

Step-by-step Explanation:

The given expression

$m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

And we have to solve for x₁

So,

Lets solve for x₁.

$m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

Multiply both sides by x₂ - x₁

$m(x_{2}-x_{1})= (x_{2}-x_{1})\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

$m(x_{2}-x_{1})= (y_{2}-y_{1})$

$mx_{2}-mx_{1}= (y_{2}-y_{1})$

$-mx_{1}= y_{2}-y_{1}-mx_{2}$

Divide both sides by -m

$\frac{-mx_{1}}{-m}= \frac{y_{2}-y_{1}-mx_{2}}{-m}$

$x_{1}= \frac{mx_{2}-y_{2}+y_{1}}{m}$

Therefore, $x_{1}= \frac{mx_{2}-y_{2}+y_{1}}{m}$

Question # 23 Solution

Answer:

$n= \frac{bx}{-b + x}$

Step-by-step Explanation:

The given expression

$\frac{nx}{b}-x=x$

And we have to solve for n

So,

Let's solve for n.

$\frac{nx}{b}-x=x$

Multiply both sides by b.

$-bn + nx = bx$

Factor out n.

$n(-b + x)= bx$

Divide both sides by -b + x.

$\frac{n(-b + x)}{-b + x}= \frac{bx}{-b + x}$

$n= \frac{bx}{-b + x}$

Therefore, $n= \frac{bx}{-b + x}$

<em>Keywords: solution, equation</em>

<em>Learn more about the solution of equations from brainly.com/question/12864981</em>

<em>#learnwithBrainly</em>

6 0

3 years ago

of the pets in the pet show 5/6 are cats.4/5 of the calico cats what fraction of the pets are calico cats

Bond [772]

The answer is 0.664 because you have to divide 4/5 and 5/6

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3 years ago

The most popular roller

GarryVolchara [31]

4/12 chance of dying

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1 year ago