Question

Help Soon!!!

Answer 1

for 1 person?
for 2 ?
for 3?

draw lines to find out the answer for small number of ppl.

for n=4, 6 handshakes.

look carefully at the sequence of numbers.

what numbers do you count for small n?

Answer 2

1=0
2=1
3=3
4=6
5=10
6=15
I can't figure out a formula

Answer 3

so far it's correct.

what do you add from one number to the next?