October 20th Teaser Solution /span> Brain Teasers: A brain teaser is a form of puzzle that requires thought to solve. It often requires thinking in unconventional ways with given constraints in mind; sometimes it also involves lateral thinking. Logic puzzles and riddles are specific types of brain teasers. Today's can be found below.... The Teaser 1. That attorney is my brother, testified the accountant. But the attorney testified he didn't have a brother. Who is lying? 2. How many 5-digit numbers are there that do not contain the numbers 3 and 5, and are multiples of 4? (It cannot start with 0, ie. 01234 is not a 5 digit number)   The Solution 1. Neither, the accountant was his sister. 2. The rule of divisibility says that a number is a multiple of 4 if its last 2 numbers are multiples of 4. So the last 2 numbers can be 21 different options:00, 04, 08, 12, 16, 20, 24, 28, 40, 44, 48, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96 because they are multiples of 4 and do not have 3's or 5's. We have the last 2 digits we need to know how many can be in the first digit: 1, 2, 4, 6, 7, 8, 9 and the second and third numbers can have these 7 and number 0 too.