Sunday Times Teaser 2735 – Two to Choose
by Ian Kay
Published: 22 February 2015 (link)
I told Sue a two-figure number and I told Terry another two-figure number, one of which was a multiple of the other. I explained this to them but knew that neither of them would be able to work out the other number. (In fact, if they had to guess the other number Sue had three times as many choices as Terry — but I did not tell them that.) When Sue confirmed that it was impossible for her to work out Terry’s number, he was then able to work out her number.
What were their numbers?