Answer:
The radius of hole is 5 feet
Step-by-step explanation:
Depth of conical hole = 9 feet
Let the radius of hole be r
Volume of conical hole =
So, Volume of conical hole =
We are given that volume of a CONE-shaped hole is 75pi ft cubed.
So,



r=5
Hence The radius of hole is 5 feet
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.