Problem number 22. Michael chose a positive number, multiplied it by itself, added 1, multiplied the result by 10, added 3, and multiplied the result by 4. His final answer was 2012. What number did Michael choose? 11, 9, 8, 7, or 5. So for this problem we have to work backwards. So here is the number 2012, which was his final answer. And as we see, it said he multiplied his result by 4. So this means we have to divide it by 4, and the answer is 503. Before that, he added 3, so we have to subtract 3. 503 minus 3 is 500. Then he multiplied the result by 10, which means we have to divide this by 10, which gives us 50. 500 divided by 10 is 50. And before that, he had added 1, so we have to subtract 1, so now we're down to 49. So the first thing Michael had done was multiply the number by itself. We need to find a number that multiplied by itself gives us 49, which is 7, because 7 times 7 is 49, which means his original positive number was 7, which means our answer is D.

math problem

reverse calculation

square number

original number

solution process