Tyrone is y years old and his younger sister is 3 years old. Their combined ages total 12 years. What equation could you use to find Tyrone's age?

There are 40 girls and 32 boys who want to participate in 6th grade intramurals. if each team must have the same number of girls and the same number of boys, what is the greatest number of teams that can participate in intramurals? how many girls and boys will be on each team?