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katrin [286]
3 years ago
7

Brian can lay a slab of concrete in 6 hours, while Greg can do it in 4 hours. If Brian and Greg work together, how long will it

take?
Mathematics
1 answer:
anastassius [24]3 years ago
5 0

Answer:

2 2/5 hours

Step-by-step explanation:

In 6 hours Brian can lay 1 slab of concrete

dividing both side by 6

in 6/6 hours Brian can lay 1/6 slab of concrete

Thus, in 1 hour  Brian can lay 1/6 slab of concrete

In 4 hours Greg can lay 1 slab of concrete

dividing both side by 4

in 4/4 hours Greg can lay 1/4 slab of concrete

Thus, in 1 hour  Greg can lay 1/4 slab of concrete

Thus, total part of slab laid by both in 1 hour when they work together

1/6 + 1/4 = 4+6/(6*4) = 10/24 = 5/12

5/12 of slab of concrete is laid by both of them in 1 hour

time taken to lay 5/12 of slab = 1 hour

dividing both side by 5/12

time taken to  5/12/ 5/12 of slab = 1/5/12 hour = 12/5 hours

time taken to 1/1 of slab = 12/5 hours = 2 2/5 hours

Thus,

it takes 2 2/5 hours to lay the full slab of concrete when Brian and Greg work together,

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Carl has 9 1/2 cups of juice for a party. If each party goer gets exactly 3/5 cup of juice each, how many party goers will get t
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Answer: 158

Step-by-step explanation:

Okay so the total is 9 5/10.

Each party goer needs 6/10

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2 years ago
Find the values of x,y, and z. The diagram is not to scale.
vazorg [7]
All the angles must add to 180degrees in a triangle.

180 = 59 + 35 + x
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Hope this helps!
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3 years ago
Tom rode his horse for 4/6 a mile. Liz rode her horse for an equal distance. What fraction is equilvalent to 4/6?
frosja888 [35]

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8 0
3 years ago
A blind man wanders under a door into an empty room. After running into the walls repeatedly for a while, it stops to think and
Nostrana [21]

From the side where the man is located in the 10' by 12' rectangular room, we have;

A) 0.046

B) The average time to escape in first attempt is approximately 605.02 seconds

<h3>Which concept can be used to find the odds and time of escape?</h3>

A) From The given diagram, we have;

Width of the door = 10 - 6 - 2 = 2

Therefore, the door is 2 feet wide

Distance, d1, from the man to the side of the door closer to him is given by Pythagorean theorem as follows;

  • d1 = √(6² + 7²) = √(85)

From the furthest side of the door to the man, we have;

  • d2 = √(7² + 8²) = √(113)

According to the law of cosines, we have;

2² = 85+113 - 2×√(85)×√(113) cos(A)

Where angle <em>A </em>is the angle formed by the lines from the man to the closer and farther sides of the door.

2×√(85)×√(113) cos(A) = 85+113 - 2²

A = arccos((85+113 - 2²)/(2×√(85)×√(113)))

A = arccos (194/(2×√(9605)) ≈ 8.213°

The angle of the possible directions in which the man can turn is 180°.

Therefore;

The probability, <em>P(</em><em>E)</em>, of escaping in the first move is therefore;

  • P(E) = 8.213°/180° ≈ 0.046

B) Given that the man escapes in the first move, the shortest and longest distances the man moves are;

d1 = √(85) and d2 = √(113)

Speed of the man, <em>v </em>= 0.5 cm/sec

Therefore by unit conversion function of a graphing calculator;

  • v = (25/1524) ft./sec

The times taken are;

t1 = √(85)/(25/1524) ≈ 562.023

t2 = √(113)/(25/1524) ≈ 648.014.

Average time, <em>t </em>= (t1 + t2)/2

Which gives;

t = (562.023 + 648.014)/2 ≈ 605.02

The average time it takes the man to escape in first move is <em>t </em><em>≈</em> 605.02 seconds.

Learn more about Pythagorean theorem and probability here:

brainly.com/question/27180985

brainly.com/question/654982

brainly.com/question/24756209

#SPJ1

3 0
1 year ago
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