Last week, the ratio of laptops to desktops sold at a computer store was 2: 5. fifteen desktop models were sold. how many laptops were sold?

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

The sum of these consecutive integers is equal to 9 less than 4 times the least of the integer. find the three integers

God's gym charges a sign-up fee of $100 plus $30 per month. write an expression to represent how much someone would pay for a membership.