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2 years ago

The speed of a sparrow is x km/h in still air. When the

Mathematics

1 answer:

Semmy [17]2 years ago

4 0

Answer:

x = 5m/s

Step-by-step explanation:

Distance flying out = 12 km (headwind)

Distance flying back = 12 km (tailwind)

total distance = 12 + 12 =24 km

wind speed = 1km/h

speed going out (with headwind) = (x - 1) km/h

speed coming back (with tailwind) = (x + 1) km/h

Time taken to go out = distance going out / speed going out

= 12 / (x-1)

Time taken to come back = distance coming back / speed coming back

= 12 / (x+1)

total time = time taken to go out + time taken to come back

5 =[ 12/(x-1) ] + [ 12/(x-1)]

expanding this, we will get

5x² - 24x - 5 = 0

solving quadratic equation, we will get

x = -1/5 (impossible because speed cannot be negative)

x = 5 (answer)

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Consider the following equivalent expressions: 38÷1312 and 38⋅ab. What are the values of a and b? Give the value of a followed b

yKpoI14uk [10]

Answer:

The values of a and b are {12,13}

Step-by-step explanation:

As,

$\frac{\frac{3}{8}}{\frac{13}{12}}=\frac{3}{8}\frac{a}{b}$

We convert the division into a multiplication by inverting the denominator

$\frac{3}{8}}\frac{12}{13}=\frac{3}{8}\frac{a}{b}$

Therefore, the smallest possible non-negative whole numbers for a and b could be are 12 and 13, respectively.

7 0

1 year ago

An investor is interested in purchasing an apartment building containing six apartments. The current owner provides the followin

Vsevolod [243]

Answer:

b) 2.7632

Step-by-step explanation:

To find the mean, we multiply each value by it's probability. So

$E = 0\frac{5}{38} + 1\frac{9}{38} + 2\frac{7}{38} + 3\frac{4}{38} + 4\frac{3}{38} + 5\frac{2}{38} + 6\frac{8}{38} = \frac{1*9 + 2*7 + 3*4 + 4*3 + 5*2 + 6*8}{38} = 2.7632$

So the correct answer is:

b) 2.7632

4 0

2 years ago

Read 2 more answers

Serena estimates that she can paint 60 square feet of wall space every half -hour .Write a equations for the relationship with t

lina2011 [118]

Answer: So, the relationship with i hours as the indecent variables would be $y=120i$

Serena can't paint 400 square feet of wall space of wall space in 3.5 hours.

Step-by-step explanation:

Since we have given that

Area that she can paint = 60 square feet

Time taken = half hour = 30 minutes = 0.5 hours

Using "Unitary method, we get that

In 0.5 hours, she can paint = 60 square feet

In 1 hour, she can paint = $\dfrac{60}{0.5}=120\ sq.\ feet$

In i hours, she can paint = $120\times i\ sq.\ feet=120i\ sq.\ feet$

Let the total area she can paint be 'y'.

So, the relationship with i hours as the indecent variables would be

$y=120i$

Now, Can Serena paint 400 square feet of wall space i. 3.5 hours

We put y = 400 and i = 3.5 hours to check whether it is equal or not.

$400= 120\times 3.5\\\\400\neq 420$

Hence, Serena can't paint 400 square feet of wall space of wall space in 3.5 hours.

3 0

1 year ago

Mia records the distance traveled in x minutes in the table below, while Alexa uses a graph to record her distance traveled over

xenn [34]

Answer:

Number 1

Step-by-step explanation:

Because she travels quicker and he line is 3/4

5 0

2 years ago

Read 2 more answers

Sweettooth frozen yogurt has 12 different toppings to choose from. if they add two new topping, how many ways more can ian choos

tester [92]

Assuming that the topping order is not important, you need to use the combination to solve this question. The number of toppings is 12 and then added 2, so the number will become: 12+2= 14 toppings

From 14 toppings, ian need to choose 3. The possible ways would be:
14C3= 14!/(14-3)!3!= 14*13*12/ 3*2= 364 possible ways

7 0

2 years ago

Read 2 more answers