Final answer:
To find out how many colored pens each first grader gets, add Corinne's 84 pens to Amelia's 72 pens to get 156 pens in total, and then divide by 12 first graders resulting in each first grader receiving 13 pens.
Step-by-step explanation:
To determine how many colored pens each first grader gets, you simply need to add the number of pens Corinne has to the number Amelia has, and then divide that total by the number of first graders:
Corinne's pens: 84
Amelia's pens: 72
Total pens: 84 + 72 = 156
Now divide the total number of pens by the number of first graders:
Total first graders: 12
Pens per first grader: 156 ÷ 12 = 13
So, each first grader would receive 13 colored pens. The correct answer is D. 13 pens.