Given 3 non-sorted indexed sequence of real numbers. How many combinations are there on selecting exactly one element out of 3 elements (one from each array) with same index?
First array : a1, a2, a3, ..., an
Second array : b1, b2, b3, ..., bn
Third array : c1, c2, c3, ..., cn
One combination on selecting one element from each index is
a1, b2, c3, a4, b5, c6, ... ,cn
How many such combinations are there? My answer for this is 3^n, i.e., each index has 3 choices. Any help is highly appreciated.