Question

How many bit strings of length 15 have bits 1; 2, and 3 equal to 101, or have bits 12; 13; 14, and 15 equal to 1001 or have bits 3; 4; 5, and 6 equal to 1010?

Answer 1

I know the first part of the equation is 2^12 + 2^11 + 2^11 ...having trouble subtracting overlapping elements

Answer 2

I'd say to subtract 2^10, but I do not believe that is correct, due to the 3 overlapping...