All 28 standard domino tiles are put in a row (one after another) according to the domino rules, such that the last number of the last domino tile is equal to 5. What is the first number of the first domino tile?

Players on the school soccer team are selling candles to raise money for an upcoming trip. each player has 24 candles to sell. if a player sells 4 candles a profit of$30 is made. if he sells 12 candles a profit of $70 is made. determine an equation to model his situation?