pls pls pls help i need it rnnn

David cast a shadow 42" long at the same place and time in Emma cast a shadow 28" long. David is 66" tall. What is Emma's height

Nikolay [14]

ANSWER

Emma is 44" tall

EXPLANATION

We have that David cast a shadow 42 inches long and he is 66 inches tall.

At that same place and time, Emma cast a shadow of 28 inches.

Since they are at the same spot and time, we can conclude that the ratio of their height to shadow must be the same.

Let Emma's height be x.

The ratio of David's shadow to height is:

42 : 66 or 42 / 66

For Emma, it is:

28 : x or 28 / x

That means that:

$\begin{gathered} \frac{42}{66}\text{ = }\frac{28}{x} \\ \text{Solve for x by cross-multiplying:} \\ 42\cdot\text{ x = 66 }\cdot\text{ 28} \\ x\text{ = }\frac{66\cdot\text{ 28}}{42} \\ x\text{ = 44 inches} \end{gathered}$

So, Emma is 44" tall.

3 0

1 year ago

Is 4.5 same as 4.50?

Softa [21]

Answer:

Yes

Step-by-step explanation:

0s after all the decimals do not count

4 0

3 years ago

Read 2 more answers

The price to ship a box varies directly as the weight of the box in pounds. A box that weighs 10 pounds costs $10.90 to ship.

xenn [34]

Well we can say 10.90/10 = the cost per pound to ship the item
we can infer this from the above text so
10.90/10 = 1.09.
So 1.09 * 37 = 40.33
$40.33
or 40 dollars and 33 cents to ship the second box with a weight of 37lb (pounds).

3 0

3 years ago

which of the following is the algebraic expression that best describes the sequence 3, 9, 27, 81, 243,...?

Anton [14]

${3}^{n}$

3 0

3 years ago

Suppose there are 4 defective batteries in a drawer with 10 batteries in it. A sample of 3 is taken at random without replacemen

SSSSS [86.1K]

Answer:

a.) 0.5

b.) 0.66

c.) 0.83

Step-by-step explanation:

As given,

Total Number of Batteries in the drawer = 10

Total Number of defective Batteries in the drawer = 4

⇒Total Number of non - defective Batteries in the drawer = 10 - 4 = 6

Now,

As, a sample of 3 is taken at random without replacement.

a.)

Getting exactly one defective battery means -

1 - from defective battery

2 - from non-defective battery

So,

Getting exactly 1 defective battery = ⁴C₁ × ⁶C₂ = $\frac{4!}{1! (4 - 1 )!}$ × $\frac{6!}{2! (6 - 2 )!}$

= $\frac{4!}{(3)!}$ × $\frac{6!}{2! (4)!}$

= $\frac{4.3!}{(3)!}$ × $\frac{6.5.4!}{2! (4)!}$

= $4$ × $\frac{6.5}{2.1! }$

= $4$ × $15$ = 60

Total Number of possibility = ¹⁰C₃ = $\frac{10!}{3! (10-3)!}$

= $\frac{10!}{3! (7)!}$

= $\frac{10.9.8.7!}{3! (7)!}$

= $\frac{10.9.8}{3.2.1!}$

= 120

So, probability = $\frac{60}{120} = \frac{1}{2} = 0.5$

b.)

at most one defective battery :

⇒either the defective battery is 1 or 0

If the defective battery is 1 , then 2 non defective

Possibility = ⁴C₁ × ⁶C₂ = 60

If the defective battery is 0 , then 3 non defective

Possibility = ⁴C₀ × ⁶C₃

= $\frac{4!}{0! (4 - 0)!}$ × $\frac{6!}{3! (6 - 3)!}$

= $\frac{4!}{(4)!}$ × $\frac{6!}{3! (3)!}$

= 1 × $\frac{6.5.4.3!}{3.2.1! (3)!}$

= 1× $\frac{6.5.4}{3.2.1! }$

= 1 × 20 = 20

getting at most 1 defective battery = 60 + 20 = 80

Probability = $\frac{80}{120} = \frac{8}{12} = 0.66$

c.)

at least one defective battery :

⇒either the defective battery is 1 or 2 or 3

If the defective battery is 1 , then 2 non defective

Possibility = ⁴C₁ × ⁶C₂ = 60

If the defective battery is 2 , then 1 non defective

Possibility = ⁴C₂ × ⁶C₁

= $\frac{4!}{2! (4 - 2)!}$ × $\frac{6!}{1! (6 - 1)!}$

= $\frac{4!}{2! (2)!}$ × $\frac{6!}{1! (5)!}$

= $\frac{4.3.2!}{2! (2)!}$ × $\frac{6.5!}{1! (5)!}$

= $\frac{4.3}{2.1!}$ × $\frac{6}{1}$

= 6 × 6 = 36

If the defective battery is 3 , then 0 non defective

Possibility = ⁴C₃ × ⁶C₀

= $\frac{4!}{3! (4 - 3)!}$ × $\frac{6!}{0! (6 - 0)!}$

= $\frac{4!}{3! (1)!}$ × $\frac{6!}{(6)!}$

= $\frac{4.3!}{3!}$ × 1

= 4×1 = 4

getting at most 1 defective battery = 60 + 36 + 4 = 100

Probability = $\frac{100}{120} = \frac{10}{12} = 0.83$

3 0

3 years ago

￼pls pls pls help i need it rnnn

pls pls pls help i need it rnnn