Good morning to all my happy (and not so) readers, it took me a while to find a reasonable (or not so) riddle for the first course I'll discuss here. So let's begin with the first math riddle: I lend money from my parents, 100NIS from both of them - 50NIS from my father and 50NIS from my mother, in order to buy a t-shirt for 97NIS. I bought the t-shirt, and got change of 3NIS, while 2NIS I gave to my parents - 1NIS to each of them and 1NIS I kept for myself. Here I tried to calculate the sum of money that was involved in order to know that what I will earn later will be enough, so I started to calculate: the money still I own: 2*49NIS + the money I returned: 2NIS + the money I had kept for my self: 1NIS = 101NIS.
Where is the mistake?
Imagine there was no 100NIS and 3NIS, but 10,000USD and 2000USD and there was no two parents, but twenty people. The mistake would "cost" me much more if someone would tell me to give just let's say 100.5NIS (and here it would be 11k) to close the deal as a kindly favour for me.
Didn't like the riddle? See one of my favorite riddles Third CS Riddle (short).