Jelly Belly beans were the first jelly beans in outer space when President Reagan sent them on the 1983 flight of the space shuttle Challenger.
Three astronauts had four jelly beans left among them one night - a black, a yellow, a green and a red. No astronaut ate more than one jelly bean and the red bean was definitely eaten. According to the following statements, determine which astronaut ate which jelly bean.
1. If the second astronaut did not eat the yellow or green jelly bean, then the first astronaut ate the red bean.
2. The second astronaut ate the yellow jelly bean, unless the first astronaut ate the red jelly bean.
3. If the third astronaut did not eat the black or yellow jelly bean then the second astronaut ate the red bean.
4. If the third astronaut ate the yellow jelly bean then the first astronaut did not eat the red jelly bean.
First astronaut - red jelly bean
Second astronaut - green jelly bean
Third astronaut - black jelly bean
From statement 3, you can deduce that the third astronaut did NOT eat the red jelly bean.
Similarly, from statement 1, it can be determined that the second astronaut did not eat the red jelly bean. Therefore the first astronaut ate the red jelly bean.
From 4, then the third did not eat the yellow bean. Therefore they ate the black jelly bean since from 3, the second did not eat the red bean.
From 2, the second ate the green and the yellow bean was uneaten.
Today's brain teaser courtesy of Braingle.com.