6. Elena sells cakes for special occasions. She charges her customers a one-time design fee plus a rate for each
serving the cake yields. The table shows the cost of a cake from Elena based on the number of servings.
SERVINGS
100
150
200
250
TOTAL COST
$280
$405
$530
$655
Based on the table, what rate does Elena charge customers per serving?
$2.80 per serving
b. $2.70 per serving
c.
$3.00 per serving
d. $2.50 per serving