Take 1000 and add 40 to it Now add another 1000 Now add 30 Add another 1000 Now add 20 Now add another 1000 Now add 10 What is the total?

5000, Unless I am missing something, it is 4100. You are adding multiples of 10s, not multiples of 100s, so it would take a LOT to add to that 5th 1000. Although I don't see how either answer is a joke, I guess the point is that you can get tricked into thinking it is 5000 rather than 4100? Not sure why it says "another" 1000 the first time you add 1000 (to the original 1000), but I don't think that's the joke. The only tricks I can see is if you are not meant to add parts of it or the part that you are adding should be getting bigger each time (add 40, then 70 (40 + 30) then, 90... even that wouldn't get to 5000) but if this is the exact wording, any trick I can see would be sort-of unsatisfying. 1000 + 40 = 1040 1040 + 1000 = 2040 2040 + 30 = 2070 2070 + 1000 = 3070 3070 + 20 = 3090 3090 + 1000 = 4090 4090 + 10 = 4100, right?