Answer:
Remember, the formula is the second value minus the first value, divided by the first value times 100.
9. 50% Increase
10. 33% Decrease
11. 200% Increase
To calculate tip, simply move the decimal place 2 to the right and multiply it by the price. For example, If you want to leave a 20% tip, multiply the cost by 0.20 to get the tip amount or multiply the cost by 1.20 to get the total including tip.
12. $23.00
13. $10.50
All together, the two girls ate 8/15 of a pizza. you mulitply your fractions out of equal denominaters and get that.
