Sam goes to lunch with a friend. The total cost of lunch is $15. Sam leaves $1.50 as a tip. What percent of the total did he tip?
0.10%
1.5%
10%
15%
To calculate the percentage that Sam tipped, we need to divide the amount he left as a tip ($1.50) by the total cost of the lunch ($15) and then multiply by 100 to get the percentage.
($1.50 / $15) * 100 = 0.10 * 100 = 10%
Therefore, Sam tipped 10% of the total cost of the lunch.