Question 12
A piece of string lies on a table with parts hidden as shown. At each hidden crossing it can have either of the two pictured over-under arrangements 
and 
. If its ends are pulled, what is the probability that it has a knot?
Original printed choices: A) 1/2; B) 1/4; C) 1/8; D) 3/4; E) 3/8
Editorial note: Explain whether the printed question and choices are consistent. Give the literal mathematical result and distinguish any intended correction.
and . If its ends are pulled, what is the probability that it has a knot?Original printed choices: A) 1/2; B) 1/4; C) 1/8; D) 3/4; E) 3/8
Editorial note: Explain whether the printed question and choices are consistent. Give the literal mathematical result and distinguish any intended correction.