Final answer:
Gina's hair grew 3/8 inch per month, while Marisa's hair grew 5/8 inch per month.
Step-by-step explanation:
To find out how much each girl's hair grew in one month, we can divide the total growth by the number of months. Gina's hair grew 1 1/8 inches in 3 months, so we can divide 1 1/8 by 3 to find out how much it grew in one month. 1 1/8 divided by 3 is 3/8 inch per month, so answer option a) Gina's hair grew 1/4 inch per month is incorrect.
Marisa's hair grew 1 1/4 inches in 2 months, so we can divide 1 1/4 by 2 to find out how much it grew in one month. 1 1/4 divided by 2 is 5/8 inch per month, so answer option c) Marisa's hair grew 5/8 inch per month is correct.