**me again.. i thought I had it...**

I thought that I had it but all of my answers are slightly off. I cannot figure out why...

you do a binomial right?

so for n=10 r=5,6,7,8,9,10 p=(1/3) q=(2/3) and nCr= 10!/r!(10-r)!

I cannot figure it out.

for example for r=7 I got nCr=120 and .0163 the answer given is .0178... anyway I wind up with .2132 instead of .2163. It is very frustrating... any help would be GREATLY appreciated!