91. To get the number in the fourth column, you add the numbers in column 1 and 2, then multiply by the number in column 2. f(n,m) = (n + m) * m
For example, f(2,3) = (2 + 3) * 3 = 15. Thus f(6,7) = (6 + 7) * 7 = 91
Three philosophers are taking a nap under a tree. While they’re asleep, a small boy smears their noses with red berries. When they awake, they each begin to laugh, thinking the other two are laughing at each other.
But then one philosopher stops laughing, realizing his nose is red too. How did he come to this conclusion?
Let’s call the philosopher’s A, B and C. A reasoned that B was confident his nose wasn’t red. If B saw A’s nose wasn’t red, he would be surprised that C was laughing, because C would have nothing to laugh at. But B wasn’t surprised, therefore, A correctly reasoned his nose was smeared.
The 17 items in your shopping cart weigh 8 pounds. But when your daughter puts in a ball, poster board and yo-yo the shopping cart weighs less. How is that possible?
54325. Rather than being a mathematical solution, the answer is derived by prepending (putting in front of) the value on the left side of the equation with the previous answer. So for 3 you take 25, the previous answer, and put 3 in front, giving you 325. Then you put 4 in front to get 4325 and lastly, put 5 in front to get 54325.