five-digitsinceStep-by-step explanation:
Ummm.....I have never done this before but I THINK what your supposed to do is find the lcm of all the pairs you can get from those 3 numbers.
so lcm(16,56)=112
lcm(56,120)=840
lcm(16,120)=240
Now take any number from this and take the lcm of that
lcm(112,840)=1680
that is the number if you take the lcm of any of them so it is the lcm of them all but it is not a number. so 16,56, and 120 are divisible by 2 I just multiplied 1680 by 2 until I got the highest possible 5 digit number which was 53760
Hope that helps :)