What is 7 29/80 as a mixed number with a decimal

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults.how many students and adults went if the ticket charge was $42.75

Afamily went out to dinner and their bill was $113.if they want to leave a 19% tip, how much should they leave.

Which pair of numbers is relatively prime? a. 105 and 128 b. 130 and 273 c. 205 and 350 d. 273 and 333