A total of 290 people attended the high school play. The admission prices were $14 for​ adults, $7 for high school​ students, and $3 for children not yet in high school. The ticket sales totalled $2040 The principal suggested that next year they raise prices to $17 for​ adults, $8 for high school​ students, and $4 for children not yet in high school. He said that if exactly the same number of people attend next​ year, the ticket sales at the higher prices will total $2470 
How many​ adults, high school​ students, and children not yet in high school attended this​ year?