You are given a math word problem and you are supposed to apply multiple mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
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Question: mrs. hilt saw a rollercoaster . 7 students rode the rollercoaster every 5 minutes . how many students rode the rollercoaster in 15 minutes ?

Answer: 21


Question: divide 39 balloons into 7 equal groups . how many balloons are there in each group ?

Answer: 5.571428571428571


Question: carol was sending out birthday invitations to her friends . if each package of invitations she bought had 9 invitations in it and she bought 5 packs how many friends can she invite ?

Answer:
45