KernelMuncher writes: Australia's Royal Air Force has been left red-faced after a job ad asked applicants to solve a complex math problem was revealed to be unsolvable. The service posted the puzzle in a bid to attract the country's best minds to its ranks. "If you have what it takes to be an engineer in the Air Force call the number below," it read above a complicated formula which candidates had to crack. But there was a slight difficulty. The problem had typos and ended up not giving potential operatives the correct contact information.