You are given a math word problem and you are supposed to apply a single mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report final the numerical answer.

[EX Q]: Andrew spent 3 day working on his Science report . He worked for 2.5 hours each day . How many hours did he work ?
[EX A]: 7.5

[EX Q]: Adolfo made a tower with 35 blocks . He added some more blocks and now he has 65 blocks . How many did he have to add ?
[EX A]: 30

[EX Q]: Sam has 86 yellow and 20 green marbles . Joan took 25 of Sam 's yellow marbles . How many yellow marbles does Sam now have ?
[EX A]:
61