Use gauss's approach to find the following sums a. 1+2+3+4..+999 b. 1+3+5..+997

Note that we're adding 999 terms in , so is summing together 999 pairs of numbers that add to 1000:









This time, adds up 499 numbers - we can determine this by finding the value of such that - that each add up to 998, so

Ithink it’s b, hope this .