Recent content by Happyzor

Ah ok, thanks. I was thinking order mattered and all, but now its clear order doesn't matter. There is only one way to choose the two birds. Then the 3rd combination is the combinations with the other 5 birds. Thanks a bunch for clearing it up.

Homework Statement You have 7 birds lined up to feed. Only 3 birds can feed at a time. Two of the 7 birds do not like to feed with each other. How many combinaions can be formed?Homework Equations C(n,k)=n!/k!(n-k)!The Attempt at a Solution Attempted solution C(7,3)-C(7,2)=21. That is the...

Thanks for your help. I didn't really understand what you meant, but I got help from someone else. I really appreciate it!

Why are they both equal to 2n? I understand why n*P({a1, a2, · · · , an}) is equal to 2n but why is the other one also 2n? Thanks for your help.

Did you remember to convert to kelvin?

Homework Statement (a) Use induction to show that if n(A) = n then n(P(A)) = 2^n. n(A) is the cardinality of set A. P(A) is the power set of A.Homework Equations The answer is We apply induction to prove the claim. If n = 0 then A = null and in this case P(A) = {null}. Thus n(P(A)) = 1 =...

I'm a newb but I'll try to help -_-. Try differentiating V=25h^2 with respect to t. Since you know dV/dt and h, you can figure out the answer.

I'm pretty sure this is Newton's Law of Cooling. The problem states that the change in temperature(derivative) is proportional(C) to the difference between the two temps(TempCoffee-20). So the equation would look like Change in Temp=(Proportional Constant)X(Difference in temperature). From...