Hi primeimplicant,

where are you getting stuck with these?

For 1)

probably need to be positive integers >0.

Are any of the numbers allowed to be zero?

If they are allowed to be negative or non-integers, that leaves infinitely

many solutions.

-14+1+2, -15+1+3 etc

Hence, start with 1, add 2 and find out what is.

Then start again at 1, add 3 and find out what is.

When finished with 1, go on to 2 and make sure you leave out all numbers

less than 2.

Then go on to 3, leaving out all numbers less than 3.

Continue until done, there are only a few.