Question 605754
Look for the pattern and then since the 10th term is not far into the sequence, we can just evaluate it: 

So we start with 1 and then added 2 to get the next number (3) and then from there we added 3 to get the next number (6) and from there.... 
Do you see a pattern?
  
(HINT: 
Let's say I wanted to find the 5th term:

I have 
1+2+3+4+5=15)

Google it: Gauss determined how to find the 100th term in the sequence using a very neat formula-- he added the first and last terms and then the second and second last... and noticed something... this is another way to do this question


I will let you do the rest, hopefully this helps get you on the right track