#please helpp
26 messages · Page 1 of 1 (latest)
right, so i think part 1 is saying,
Consider the set {1,2,3,4,5}
give me a subset, of length 3, which doesnt have any 2 consecutive integers
so, 1,2,4 is not allowed
as 1 and 2 are consecutive
but 1,3,5 is
i think its the only one actually
now the function U(n, k) is asking how many of these subsets we can actually make which follow that rule
so for U(5,3) [our part 1] the answer is 1
so for U(n, 1) , we can only choose one number from our set,
there are n numbers to choose from so the answer is just n
U(n,1)=n
for U(n,2) i think its a lil trickier
lmk if you follow so far
Okay, for u(n,2) I think we may need to try some cases.
If n =2, then we have no solutions, as both would have to be chosen, but since they're consecutive wouldn't be allowed
If n=3, U(n,2) = 1, the only solution is 1,3
If n=4 U(n, 4) = 3
1,3 2,4 1,4
Let's try one more
N= 5, u(n, 5)
1,3 1,4 1,5 2,4 2,5 3,5
=6
Think you can go from here?
Np
.solved