Answer:
7 hours 30min
Step-by-step explanation:
Step one :
Given data
We are told that Erica can paint 1 room in 5hours
Her work rate is 1/5 room per hour
And also with the assistance of her friend they can paint 1 room in 3 hours
Hence their combined work rate is 1/3 room per hour
Step two
The combined work expression is
1/A+1/B=1/T
Where A=Erica's work rate
B=Rachael's work rate
T=combined work
1/5+1/B=1/3
1/B=1/3-1/5
1/B=5-3/15
1/B=2/15
B=15/2
B=7.5 hours
It will take Rachel 7 hours 30min to paint the room
63% decrease.
0.63•80=50.4kg
80kg-50.4kg=29.6kg
+1,-1 and your other would be 1,1
The value of x is 2 and the length of JK is 4
<h3>How to solve the unknown variables?</h3>
The given parameters from the circle are:
- Center = Point S
- Segment JK = 8
- Segment LK = 2x + 4
- Congruent SN = SP = 7
The lines SR and SQ are the radii of the circle P
This means that lines JK and JL are congruent
So, we have:
JK = KL
Substitute LK = 2x + 4 and JK = 4
4 = 2x + 4
Rewrite the above equation as:
2x + 4 = 8
Subtract 4 from both sides
2x + 4 - 4 = 8 - 4
Evaluate the difference
2x = 4
Divide both sides by 2
2x = 4/2
This gives
x = 2
Substitute x = 2 in LK = 2x + 4
LK = 2*2 + 4
Evaluate the product of 2 and 2
LK = 4 + 4
This gives
LK = 8
The point N divides JK into 2 equal segments
So, we have
JN = JK/2
JN= 8/2
JN = 4
Hence, the value of x is 2 and the length of JK is 4
Read more about circles at:
brainly.com/question/11833983
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The paint mixer should mix 1.238 gallon paint that is 30 % gloss and 2.512 gallon paint that is 15 % gloss to get 3.75 gallon of paint that is 20 % gloss.
In this question we must determine the correct volumes of each paint to obtain a 20 % gloss with paint by means of weighted averages:
(1)
Where:
- Proportion of the paint that is 30 % gloss.
- Concentration ratio of the paint that is 30 % gloss.
- Concentration ratio of the paint that is 15 % gloss.
- Resulting concentration ratio
If we know that
,
and
, then the proportion of the paint that is 30 % gloss is:




And the quantity of gallons needed of each paint are:
Paint (30 % gloss)


Paint (15 % gloss)



The paint mixer should mix 1.238 gallon paint that is 30 % gloss and 2.512 gallon paint that is 15 % gloss to get 3.75 gallon of paint that is 20 % gloss.
To learn more on weighted averages, we kindly invite to check this question: brainly.com/question/18554478