If I have 56 nuclotide bases and each DNA model can contain 4 different bases, how many different combinations of DNA models can I have?

Guest Oct 23, 2017

#4**0 **

My understanding is that the 4 bases can be repeated, such as:AAAA, CCCC, GGGG and TTTT. The formula I used is the Binomial expansion with repeats allowed.

Guest Oct 23, 2017

#6**+1 **

You could be right. I have a Math Dictionary and gives the following:

1-Combinations with repetitions: Each element can be chosen more than once for a particular combination. The number of possible combinations is then [n + r -1], r.

Example n=4, r=2 a, b, c, d: aa, ab, ac, ad,

bb, bc, bd,

cc, cd,

dd,

[4 + 2 -1], 2 =5C2 = 10

Guest Oct 23, 2017