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
Answer:
A
Step-by-step explanation:
This can be easily understood using the triangle inequality theorem:
"In a triangle, the combined lengths of any two sides must always be greater than the length of the third side."
- Is 10+5 greater than 4? YES
- Is 10+5 greater than 5? YES
- Is 5+4 greater than 10? No!
Since all of them doesn't hold true, we cannot make any triangle. The answer is A, 0.
Answer:
475.2
Step-by-step explanation:
682 is 1.55 of the original amount so 1.55x=682
682/1.55=440
440*1.08=475.2
Hello,
The sum of volumes of the two spheres is
4/3*π*a³+4/3*π*b³=4/3*π*c³
c=∛(a³+b³)=∛(3³+5³)=∛152=5.336803297...≈5.34 (cm)
<span> When area is equal 1120. We can write an equation
(x+4)(-x+64)=1120
-x²-4x+64x+256=1120
-x²+60x+256-1120=0
-x²+60x-864=0
D=b² - 4ac= 3600-4*864=144, √D=12
x= (-b+/-√D)/2a
x=(-60+/-12)/(-2)
x=24, x=36
For x=24
(x+4)=24+4=28
(-x+64)=(-24+64)=40
For x=36
(x+4)=36+4=40
(x-64) =(-36+64)=28
So sides should be 28 and 40 in.
We did not get any extraneous solutions. They could be if we get negative length side, for example. They can come because a quadratic equation can
give positive and negative numbers because a^2 and (-a)^2 give the same positive number.
We chose to solve this equation using formula for quadratic equations, because this equation has too big numbers to solve it using other methods.
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