Question

3. Tom, Sam and Matt are counting drum beats.
Tom hits a snare drum every 4 beats.
Sam hits a kettle drum every 10 beats.
Matt hits a bass drum every 12 beats.
Tom, Sam and Matt start by hitting their drums at the same time.
How many times are each of their beats heard before Tom, Sam and Matt next hit
their drums at the same time?

Answer 1

Answer:

When 60 beats are heard, Tom hits 15 snare drums, Sam hits 6 kettle drums, and Matt hits 5 bass drums.

Step-by-step explanation:

The Least Common Multiple ( LCM )

The LCM of two integers a,b is the smallest positive integer that is evenly divisible by both a and b.

For example:

LCM(20,8)=40

LCM(35,18)=630

Since Tom, Sam, and Matt are counting drum beats at their own frequency, we must find the least common multiple of all their beats frequency.

Find the LCM of 4,10,12. Follow this procedure:

List prime factorization of all the numbers:

4 = 2*2

10 = 2*5

12 = 2*2*3

Multiply all the factors the greatest times they occur:

LCM=2*2*3*5=60

Thus, when 60 beats are heard, Tom hits 15 snare drums, Sam hits 6 kettle drums, and Matt hits 5 bass drums.