# Close the Gates

by Jason Boomer

A computer engineer would recognize those diagrams as (sideways) binary logic gates. The objective is to find the sets of inputs for which the given outcome is "closed," i.e. 1. Reading the inputs as 5-bit numbers from left to right, the inputs that satisfy each of the diagrams are as follows:

A) 00100, 00101, 00110, 00111, 01101, 01111, 10000, 10010, 10100, 10101, 10110, 10111, 11101, 11111

B) 00000, 00001, 01000, 01001, 01010, 01100, 01101, 01110, 10000, 10001, 10010, 10100, 10110, 11000, 11001, 11010, 11100, 11110

C) 00000, 00001, 00010, 00011, 00100, 00101, 00110, 00111, 01011, 01110, 10010, 11000, 11001, 11010, 11011, 11100, 11101, 11110, 11111

D) 00000, 00010, 00101, 00110, 00111, 01110, 01111, 10110, 10111, 11110, 11111

E) 00000, 00010, 01000, 10000, 10010, 10100, 10110, 11000, 11001, 11010, 11011, 11100, 11101, 11110, 11111

Next you must evaluate the set notation; find all of the inputs that satisfy, for example, B and C but not E for number 2.

1) 00010, 01111, 10111; 2) 00001, 01110; 3) 00100 4) 00001, 10010; 5) 10010; 6) 01111, 10111; 7) 10011

Convert binary to decimal and decimal to letters (A=1, B=2, etc.) and you get 1) BOW; 2) AN; 3) D; 4) AR; 5) R; 6) OW; 7) S which gives the answer, **BOW AND ARROWS**.