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3 years ago

Tim and Jim are working on a school project together. If he had to work by himself, it would take

Mathematics

1 answer:

Vladimir [108]3 years ago

4 0

Answer: 6 hours

Step-by-step explanation:

Given, Tim and Jim are working on a school project together.

Tim takes 10 hours to complete the school project.

If Jim worked alone, it would take him 15 hours

Let t be the time they both take if they work together.

Then, $\dfrac{1}{t}=\dfrac{1}{\text{Time taken by Tim}}+\dfrac{1}{\text{Time taken by jim}}$

$\Rightarrow\ \dfrac{1}{t}=\dfrac{1}{10}+\dfrac{1}{15}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{3+2}{30}=\dfrac{5}{30}\\\\\Rightarrow\dfrac{1}{t}=\dfrac{1}{6}\\\\\Rightarrow t=6$

So, it will take 6 hours to complete the school project together .

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Perform the indicated operation. 6 - 2i/5 + 3i =

fgiga [73]

I am gonna assume it is C)9/4 - 1/2i

5 0

3 years ago

Read 2 more answers

a yard width is 2 less than it's length. If the perimeter of the yard is 20 feet determine the length and the width of the yard

Arte-miy333 [17]

Answer:

The length is 6 feet and the width is 4 feet

Step-by-step explanation:

Let x represent the length of the yard

The width can be represented by x - 2, since it is 2 less than the length.

Use the perimeter formula, P = 2l + 2w, where l is the length and w is width

Plug in the expressions and perimeter:

20 = 2x + 2(x - 2)

Solve for x:

20 = 2x + 2x - 4

20 = 4x - 4

24 = 4x

6 = x

So, the length is 6. Plug this into x - 2 to find the width

x - 2

6 - 2

= 4

So, the length is 6 feet and the width is 4 feet

5 0

3 years ago

The perimeter of equilateral triangle ABC is 81/3 centimeters, find the length of the radius and apothem.

MAXImum [283]

There is a typo error, the perimeter of equilateral triangle ABC is 81/√3 centimeters.

Answer:

Radius = OB= 27 cm

Apothem = 13.5 cm

A diagram is attached for reference.

Step-by-step explanation:

Given,

The perimeter of equilateral triangle ABC is 81/√3 centimeters.

Substituting this in the formula of perimeter of equilateral triangle = $3\times\ side$

$3\times\ side$ $=[tex]81\sqrt{3}$

$Side = \frac{81\sqrt{3} }{3} =27\sqrt{3} \ cm$

Thus from the diagram , Side $AB=BC=AC= 27\sqrt{3} \ cm$

We know each angle of an equilateral triangle is 60°.

From the diagram, OB is an angle bisector.

Thus $\angle OBC = 30$ °

Apothem is the line segment from the mid point of any side to the center the equilateral triangle.

Therefore considering ΔOBE, and applying tan function.

$tan\theta =\frac{perpendicular}{base} \\tan\theta=\frac{OE}{BE} \\tan\theta=\frac{OE}{\frac{27\sqrt{3}}{2} } \\tan30\times {\frac{27\sqrt{3} }{2} }= OE\\\frac{1}{\sqrt{3} } \times\frac{27\sqrt{3} }{2} =OE\\$

Thus ,apothem OE= 13.5 cm

Now for radius,

We consider ΔOBE

$cos\theta=\frac{base}{hypotenuse} \\cos30= \frac{BE}{OB} \\Cos30 = \frac{\frac{27\sqrt{3} }{2}}{OB} \\OB= \frac{\frac{27\sqrt{3} }{2}}{cos30} \\OB= \frac{\frac{27\sqrt{3} }{2}}{\frac{\sqrt{3} }{2} } \\OB =27 \ cm$

Thus for

Perimeter of equilateral triangle ABC is 81/√3 centimeters,

The radius of equilateral triangle ABC is 27 cm

The apothem of equilateral triangle ABC is 13.5 cm

4 0

3 years ago

Jordan lives 6 kilometers due south of his parents' house and 4 kilometers west of his grandparents' house. On his birthday, Jor

rusak2 [61]

Answer:

Step-by-step explanation:

The direction of movement of Jordan on his birthday forms a right angle triangle. His movement from his house to his parents due south represents the opposite side of the right angle triangle. His movement due west represents the adjacent side and the movement back home along the straight line, d represents the hypotenuse. To determine d, we would apply the Pythagorean theorem. Thus

d² = 6² + 4² = 52

d = √52 = 7.2 km

The total distance that he drove on his birthday is

6 + 4 + 7.2 = 17.2 km

5 0

3 years ago

HELPPP A. 9 B. 20 C. 16 D. 4

serious [3.7K]

Answer:

C 16

Step-by-step explanation:

Using ratios

3:12

12/3=4

4:x

4*4=16

x=16

4:16

hope this helps:)

6 0

3 years ago