0 votes 0 votes How many $4$-element $DNA$ sequences do not contain the base $T?$ contain the sequence $ACG?$ contain all four bases $A, T, C,$ and $G?$ contain exactly three of the four bases $A, T, C,$ and $G?$ Combinatory kenneth-rosen discrete-mathematics counting descriptive + – admin asked Apr 28, 2020 • edited Apr 28, 2020 by Lakshman Bhaiya admin 354 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.