Answer:
B
Step-by-step explanation:
Do you remember when you were learning about
Least Common Multiple (LCM) ? And you were
wondering what on Earth you would ever need it for ?
THIS IS IT !
The amount of time after 8 PM when the lights will flash
together again is the LCM of 20 seconds and 30 seconds.
Do you remember how to find it ?
... When 20 is prime-factored, you have 2 · 2 · 5 .
... When 30 is prime-factored, you have 2 · 3 · 5 .
... So the Least Common Multiple of 20 and 30 is 2 · 2 · 3 · 5 = 60 .
The lighthouses will flash together again in 60 seconds after 8 PM.
That'll be 8:01 PM.
Answer:
r = 29.82
Step-by-step explanation:
We have the equation r/7.1 = 4.2 and are asked to solve for r.
To solve, we need to isolate r, do as followed and multiply 7.1 from both sides:
r/7.1 = 4.2
r = 29.82
Answer:
$30, $75, $45
Step-by-step explanation:
We can set up an equation, where x is an unknown value:
2x+5x+3x=150
10x = 150
x=15
Now that we know what x is, we can plug x in to solve for 2x, 5x, and 3x:
2x=2*15=30
5x=5*15=75
3x=3*15=45
Therefore, the answer is $30, $75, $45
Answer:
Step-by-step explanation:
Given that tank has the shape of inverted circular cone
Height = 10 feet and radius = 4 feet
After water pumped out height = 5 ft
Hence volume of water pumped out = 
Here we have r/h is constant always
Hence 
Substitute to get volume of water pumped out = 
Mass of water = density x volume = 
Work done = force x displacement
= mass x accen x displacement
Here acceleration = gravity = 32.2 ft/sec^2
Displaement = height reduced = 5 ft
W=2912(32.2)(5)\pi =468832\pi foot -pound
