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2 years ago

11

If 12 workers can dig a tunnel in 100 days, how long will it take 20 workers to dig the tunnel

1 answer:

Paraphin [41]2 years ago

3 0

Answer:

60 days.

Step-by-step explanation:

This is a proportion question. You compare two ratios. Unfortunately it is an inverse ratio.

12 = k/100 Multiply both sides by 100

1200 = k

20 = k/x Multiply both sides by x

20x = k

20x = 1200 Divide by 20

20x/20 = 1200/20

x = 60 days.

An inverse proportion works by making a constant k. The constant k makes the days shorter when the number of people increases. You should expect that. More people , less time.

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At Tech Express, 40% of the customers purchases small coffee and 60% purchases medium. Of those customers purchasing small coffe

Dvinal [7]

Answer and explanation:

Given : At Tech Express, 40% of the customers purchases small coffee and 60% purchases medium. Of those customers purchasing small coffee, 30% prefer decaf. Of those purchasing medium coffee, 50% prefer decaf.

Let $A_1$ customer purchase small coffee.

i.e. $P(A_1)=40\%=0.4$

$A_2$ customer purchase medium coffee.

i.e. $P(A_2)=60\%=0.6$

Let B be the customer purchase prefer decaf.

So, $P(B|A_1)=30\%=0.3$

$P(B|A_2)=50\%=0.5$

(a) What is the probability that the next customer will request medium and decaf coffee?

i.e. $P(A_2\cap B)=P(A_2)\times P(B|A_2)$

$P(A_2\cap B)=0.6\times 0.5$

$P(A_2\cap B)=0.3$

(b) What is the probability that the next customer prefers decaf?

i.e. $P(B)=P(A_1\cap B)+P(A_2\cap B)$

$P(B)=P(A_1)\times P(B|A_1)+P(A_2)\times P(B|A_2)$

$P(B)=0.4\times 0.3+0.6\times 0.5$

$P(B)=0.12+0.3$

$P(B)=0.42$

(c) If the next customer prefers decaf, what is the probability that small is requested?

i.e. $P(A_1|B)=\frac{P(A_1\cap B)}{P(B)}$

$P(A_1|B)=\frac{0.12}{0.42}$

$P(A_1|B)=0.28$

3 0

3 years ago

The diameter of OC is 18 com long. What is the length of an arc with a measure of 100 degrees

butalik [34]

Answer:

15.7 cm

Step-by-step explanation:

Radius = 18/2 = 9cm

(100/360) × 2 × 3.14 × 9

15.7 cm

8 0

3 years ago

Gabriela works at a nearby electronics store. she makes a commission of 14% on everything she sells. if she sells a camera for $

Alexxandr [17]

Her commission is from 14% of the camera, which is $589.00
So her commission is 0.14*589=82.46
The answer is $82.46

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4 years ago

What inequality is shown by the graph? algebra 1

UkoKoshka [18]

We are working on the same thing lolll

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3 years ago

A) Use numbers 7,5,6 and 3, only once each, to create an expression that equals 75. You may use addition, subtraction, multiplic

bearhunter [10]

6(7+5) + 3 =
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If you wanted to continue and solve...

72 + 3 =
75

6 0

3 years ago