1. Andrey named all natural numbers from 180 to 220 inclusive ("one hundred eighty", "one hundred eighty one", etc.). How many words did he say?
Solution. A total of 41 numbers are named. In each, the hundreds place is named (a total of 41 words). In addition to the hundreds place, the numbers 180, 190, 201-220 each contain one more word (this is 22 words). The number 200 does not contribute any more words, while the remaining 18 numbers each contain two more words. In total, $41+22+2 \cdot 18=99$ words.