1. (7th grade) Several girls (all of different ages) were collecting white mushrooms in the forest. The collected mushrooms they distributed as follows: the youngest received 20 mushrooms and 0.04 of the remainder. The next oldest received 21 mushrooms and 0.04 of the remainder, and so on. It turned out that everyone received an equal amount. How many mushrooms were collected and how many girls were there?
1. Let the number of collected mushrooms be denoted by $x$. Then the youngest girl received $20+(x-20) \cdot 0.04$ mushrooms. The second girl received $19.392+0.0384 x$. Both received the same amount. By setting up the equation and solving it, we find $x=120$. There were 5 girls, each received 24 mushrooms.