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.
Average speed: distance traveled/elapsed time
= 75/30
= 2.5 meters per second.
Best of Luck!
Answer:
Step-by-step explanation:
So first, we know (-x,-y) reflected across y axis is (x,-y). and (x,y) reflected across y axis is (-x, y). So we can apply this to get (-4,-1) to (4,-1). (2,6) to (-2,6).
Answer:
Runner 1
Step-by-step explanation:
Runner 1's speed is the slope of the line = (20-0)/(2-0) = 10
Runner 2's speed is the slope of the line = 8.5 (the coefficient of t)
Runner 3's speed is slope = (36-18)/(4-2) = 9
The fastest pace, therefore is of runner 1, because 10>9 AND 10>8.5
