what is the least number that can be exactly divided by 56, 63 and 84?

Question

curry · Answer

she is asking for the lcm i bleive not lcf

anonymous · Answer

curry is right.

zarkon · Answer

504

curry · Answer

zarkon help me

anonymous · Answer

To find the lcm of two numbers a and b:
Simply divide (a * b) by their gcd

anonymous · Answer

slip on my part.

zarkon · Answer

lcm(a,b,c)=lcm(a,lcm(b,c))

anonymous · Answer

for all those numbers up their, their gcd is 7.
lcm(56, 63) = 504
lcm(84, 63) = 252

it becomes clear that lcm(504, 252) is 504

anonymous · Answer

there* I can't believe I misspelled that :(

asnaseer · Answer

another way to look at this is to write each number as a product of their prime factors, so:
$$56=2^3*7$$$$63=3^2*7$$$$84=2^2*3*7$$
then just select every unique prime factor (picking the one with the largest power if two or more numbers share a prime) and multiply these together to get your Lowest Common Multiple - see diagram:
|dw:1322172676762:dw|
so LCM(56, 63, 84) is:$$2^3*3^2*7=504$$