How many same-sized units are equal to 771 kilograms?

Answer 1

If each unit must consist of a WHOLE NUMBER of smaller units and the weight of each unit must be a WHOLE NUMBER of kilograms, then THE SIZE WILL BE A PRIME NUMBER (a positive integer that is divisible only by 1 and itself).

There are only two prime numbers (3 and 257) that when multiplied together give 771. Thus, there may be 3 of 257-kilogram-sized units or there may be 257 of 3-kilogram-sized units.