Pilots in a pickle
For reasons unknown to us, two pilots have ended up in prison together. They share a prison cell with one open window, 30 feet above the ground.
They cannot reach the window so plan to escape by tunnel. After digging for more than 20 days, one of the pilots develops a new plan and they escape.
What was the plan?
The answer will be published in the next edition of ON AIR!. Please send your solutions to [email protected]. All entries must be received by 30th June 2018. The first correct answer drawn at random after this date will win a pair of Helios noise-cancelling headphones. Good luck!
And the winner is ...
Congratulations to Tim Murphy of Boeing, who sent the correct answer to our previous puzzle 'information sharing' and came first in the draw.
See below for the full answer:
Company A divides the amount of their contribution into two numbers, by a proportion known only to them, then privately reveal one number to Company B and the complementary to Company C. Company B adds the amount given by Company A to their own and gives that number to Company C. Company C now adds the number received by Company A and Company B to their own and can reveal the sum total for the project to the other two without anyone having to reveal how much they contributed or who contributed the least - with this method there is a minimum of three 2-way conversations.
If A contributed £100k, B contributed £60k and C contributed £120k:
A tells B £30k, and A tells C £70k (any other non-null proportion can be chosen).
B adds the number from A to its own and tells C £90k.
C adds all the number it has received (70 from A, 90 from B) and announces that the budget is £280k