What two whole, positive numbers that have a one-digit answer when multiplied and a two-digit answer when added?

Answer: 1 and 9.

More Difficult Riddles with answers

More Difficult Riddles

What type of bar gets you wet walking in and out of it but keeps you dry inside?
What type of paper can you neither read nor write on?
What types of words are these: madam, civic, eye, level?
What was never scared but became petrified, can't make a bird but can make a bat, can't live in a house but would die to have one. What is it?
What weaves webs as they grow?
What word in the English language does the following: the first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?
What word in the English language uses all five vowels plus Y in alphabetical order, and uses each only once?
What word is a plural, but when you add an "S" to the end, it becomes singular?
What word looks the same upside down and backwards?
What zips through the sky with a tail of fire and dust. It could be an omen, its origin to discuss?
What's a place you have left but didn't enter?
What's as small as a mouse but guards a house like a lion?