Three more than the product of a number and 5 is equal to 6.

What situation is an example of an observational study

Cassie is traveling 675 miles today to visit her brother and his family. so far, she has stopped for gas three times. at the first stop, she put in 7.1 gallons of gas and paid $23.79. at her second stop, she put in 5.8 gallons of gas and paid $19.08. and, at the third stop, 6.6 gallons and paid $20.39. at which stop did casey pay the most for gas?

At a book fair, joe bought 24 books at 3 for $5 and had $2 left. how much money did he have at first?