The cost of a keyboard (k) is $40 less than the cost of a printer (p). Which of these equations could model this fact?

Operations: Housekeeping Math Quiz

masha68 [24]

Answer:

Total time = 63 hours

Step-by-step explanation:

First, let us write out the information in the question:

rate at which rooms are cleaned = 20 mins/room

number of rooms = 175

one-fifth of the rooms take 40% longer to clean

Next, let us convert the extra time taken to clean the rooms from percentage to time.

40% of normal cleaning time = 40% of 20

= 40/100 × 20 = 0.4 × 20 = 8 minutes

∴ onw-fifth of the rooms take an extra 8 minutes = 28 minutes in total

Next, let us calculate how many of those rooms in the total 175 takes the extra cleaning time:

one-fifth of the rooms takes 28 minutes to clean means that:

1 in every 5 rooms out of the 175 rooms take 28 minutes to clean

∴ Number of rooms with extra cleaning time = 1/5 of 175

= 1/5 × 175 = 0.2 × 175 = 35

∴ 35 rooms take 28 minutes each to be cleaned.

Now let us calculate the total cleaning time:

if 35 rooms take the extra cleaning time, then the number of rooms that have the normal cleaning time is as follows:

175 - 35 = 140

Total time:

140 rooms taking 20 minutes per room = 140 × 20 = 2,800 munites

35 rooms taking 28 minutes per room = 35 × 28 = 980 minutes

Total cleaning time = 2800 + 980 = 3780 minutes

converting to hours (1 hour = 60 minutes)

∴ 3780 minutes = 3780 ÷ 60 = 63 hours (2 days and 15 hours)

8 0

2 years ago

Among 21- to 25-year-olds, 29% say they have driven while under the influence of alcohol. Suppose that three 21- to 25-year-olds

Vilka [71]

Answer:

0.6421

Step-by-step explanation:

In this case we have 3 trials and we have 2 options for each one. The driver has or hasn't been under alcohol influence. The probability that the driver has is 0.29 and the probabiility that the driver hasn't is 1 - 0.29 = 0.71

each trial is independent because we are assuming that the population of drivers in between 21 and 25 years old is very big.

The probability that one of them was under alcohol influence can be found by finding the probability that non of them was under alcohol influence because:

1 = p(x = 0) + p(x ≥ 1)

p(x ≥ 1) = 1 - p(0)

The probability that none of them was under alcohol influence is going to be:

0.71×0.71×0.71 = 0.3579

The probability of finding at least one driver that has been under alcohol influence is:

0.6421

4 0

2 years ago

help please !!!Kevin wants to make a mixture that is 50% lemon juice and 50% lime juice. How much 100% lemon juice should he add

Liula [17]

So basically, he wants to make mixture where lemon=lime

it is 6 gallons so
40% of 6=0.4 times 60=2.4=lemon
60% of 6=0.6 times 60=3.6=lime
so to make them equal
3.6-2.4=1.2
he must add 1.2 gallons of 100% lemon juice to make a mixture of 50% lemon and 50% lime

1.2 gallons is the answer

8 0

2 years ago

You buy a pair of jeans at a department store. Jeans 39.99 Discount -10.00 Subtotal 29.99 Sales tax 1.95 Total 31.94 a. What is

Mariana [72]

A)

if 39.99 is the 100%, what is 10 in percentage? well

$\bf \begin{array}{ccllll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
39.99&100\\
10&x
\end{array}\implies \cfrac{39.99}{10}=\cfrac{100}{x}$

solve for "x".

b)

now, with the discount, the amount is 29.99, thus if 29.99 is the 100%, what is 1.95 from it in percentage?

$\bf \begin{array}{ccllll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
29.99&100\\
1.95&x
\end{array}\implies \cfrac{29.99}{1.95}=\cfrac{100}{x}$

solve for "x".

c)

the original price is 39.99, the markup on that is 60%, how much is that?
well

$\bf \begin{array}{ccllll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
39.99&100\\
x&60
\end{array}\implies \cfrac{39.99}{x}=\cfrac{100}{60}\implies 39.99\cdot 60=100x
\\\\\\
\cfrac{39.99\cdot 60}{100}=x\implies 23.994=x$

now, after the discount, the price is 29.99, how much is 23.994 in percentage of 29.99?

well $\bf \begin{array}{ccllll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
29.99&100\\
23.994&x
\end{array}\implies \cfrac{29.99}{23.994}=\cfrac{100}{x}$

solve for "x".

8 0

2 years ago

A florist has 8 roses and 24 daffodils.she wants to make as nany identical bouquets as possible, with the same combination of ro

Paladinen [302]

They should have 3 daffodils and 1 rose in each bouquet and that will equal 8 bouquets.

8 0

2 years ago

The cost of a keyboard (k) is $40 less than the cost of a printer (p). Which of these equations could model this fact? ​

The cost of a keyboard (k) is $40 less than the cost of a printer (p). Which of these equations could model this fact?