Two lighthouses flash their lights every 20 and 30 seconds respectively. given that they flash together at 8 p.m., at what time
will they next flash together? answer:
1 answer:
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.
You might be interested in
Answer:
Yes, the ratios do form a proportion.
Exponential growth because a decay would be a fraction in the parenthesis
Look this american “ñ” hahaha
To figure out your question, just divide 999,999 by 9.
999,999/9 = 111,111
Parallel lines would have to have the same slope so the green line also has a 1/5 slope
