The correct answer is right.
An acute one would have all three acute, while an obtuse one would have at least one obtuse angle.
To find out how much is needed for 1 you will need to divide each given value by 4:
12 marshmallows / 4 = 3
8 graham crackers / 4 = 2
4 smores / 4 = 1
you then need to multiply each value by 3 :
3 marshmallows x 3 = 9
2 graham crackers x 3 = 6
1 smore x 3 = 3
therefore the answer would be :
9 marshmallows
6 graham crackers
hope this helps you
Extra 10, 10 is half of what she ordered so she received an extra 50%