Question 15
Bob removes numbered beads from a tube one at a time. He may thread a bead or discard it permanently. He can thread a bead only if the string is empty or its number is greater than the last bead threaded. The example shows two choices after 1 and 2: thread 5, or discard 5 and continue.
For the following tube, what is the greatest number of beads Bob can thread? Beads leave from the right-hand opening.
For the following tube, what is the greatest number of beads Bob can thread? Beads leave from the right-hand opening.