- #1
Natasha1
- 493
- 9
Homework Statement
You are given the following two sums:
1+2+3+...+50 = 1275 and
1+2+3+...+100 = 5050
Using these results, find the following sums. (no long methods allowed)
a) 51+52+53+...+100
b) 2+4+6+...+100
c) 1+3+5+...+99
d) 1-2+3-4+5-...+99-100
e) 100.01-100.02+100.03-100.04+... -101
2. The attempt at a solution
a) (1+2+3+...+100) - (1+2+3+...+50) = 5050 - 1275 = 3775
b) (1+2+3+...+50) + (1+2+3+...+50) = 1275 +1275 = 2550
c) stuck, need help on this one
d) (-1)+(-1)...+(-1) = -100
e) (-0.01)+(-0.01)+...+(-0.01) = 1
Could you please check a, b, d and e and help me with c? Thank you :)