Reference :- Due to popular request we are publishing the answer to Gabbo's conundrum .

Reference :-  Who would have thought that so many people couldn't solve Gabbos's riddle ?

 Two posts ago we posed this question .   You are at an intersection wondering whether to turn left or right to reach your destination . Two sisters are standing at the intersection . One sister always tells lies , and the other always tells the truth . You can ask one sister one question  . What do you ask to determine the correct direction ?

 And here is the answer .  You pick one of the sisters randomly and ask this . 

"  Will your sister tell me to go to the right ? "  . 

 If the answer is yes , then you must turn left .  

The reasoning goes like this .   If the sister you asked is the liar , she will have lied when she said the honest sister would tell you to go right . This means the correct direction is to the left . 

If the sister you asked is honest , when she says that the other sister would tell you to turn right  she is telling the truth  about the other sister who  is the liar , so you must turn left . 

If the answer is no , you must turn right .  The same logic applies . 

Should you have asked the sister who lies , she will have lied when she said her sister would say no .  Which means the honest sister would say turn right . 

If the sister you asked is honest she would answer no , because she knows the lying sister will tell you to turn left . 

This means you must turn right . 

 It's pretty obvious now Gabbo has pointed it out .  

 Parliament question time will never seem  as daunting again . 

Your comrade,  Ken .