Answer: 1 and 4. They're arranged in groups of two-digit numbers, all ending in 7 and ascending in both rows. Was this a hard math problem, or did you get the answer right? To open this safe, you have ...

you do a whole bunch of [math] problems without the word problems—and then there was always that word problem at the end, and it was always posed as, this is the difficult type,” he said.