As Jill swung through the door of the Blue Swan café one busy Saturday afternoon, she saw Jack sitting at a window table staring intently at his mobile phone, nervously sipping a coffee.
“What’s so fascinating on your phone, Jack? ”
“Jill, I could win a ten thousand dollar prize if I work out a code.”
“What code are you talking about.”
“A puzzle website is offering a promotional prize, but I have one hour to work out a code to win it.”
“Is it that difficult?” said Jill.
“Yeah, the code is based on a five-digit number that when quadrupled gives the reverse of itself, which is the number I need,” said Jack.
“Oh, that’s a tricky one. Any more information?”
“Well, there is a strange hint I can’t figure out,” said Jack with a forlorn expression.
“And what’s that?”
“The cryptic hint is: ‘The cross sum is the middle. Half the first is the second. Cube the start to get the end.’”
“I’ve run into this type of thing in my course on number theory with professor MacDooley. Does a fifty-fifty share sound ok to you, Jack?”
“Sure, Jill. What else can I say,” shrugged Jack.
Jill quickly pulled out a notepad, calculator and pen from her bag, sat down and got busy writing. Jack ordered her a cappuccino.
What would you say is the code needed to win the prize?