The Brainliest Answer!
I think the answer is 1 but 1 is divisible by any counting number therefore except 1 the lowest common factor is 2520. i think so. 
       hope that this will help u.
1 5 1
the question lacks some vial information
correct answer is 2520
question man
ya u have done this by taking LCMs and then common am i write
wat exactly is the question
The ans is 1  
if it is LCM the COMMON FACTOR IS 2520.
i hope this helped..