Sunday Times Teaser 2611 – Simple Arithmetic
by Danny Roth
Published: 7 October 2012 (link)
George and Martha are teaching their great-grandchildren some simple arithmetic. “If you add two thirties to four tens you get a hundred,” George was saying, and he wrote it like this:
“Strangely,” added Martha, there are nine different letters there, and if you allow each letter to stand for a different digit, there is a unique sum which works.”
Which digit would be missing?