Groups A, B, and C have a total of 90 books. If group B borrows 3 books from group A and gives 5 books to group C, then the books of all the books in the three groups are just equal. How many books are there in group B? Book.
甲、乙、丙三个组共有图书90本，如果乙组向甲组借3本后，又送给丙组5本，那么三个组所有图书的本书刚好相等，乙组原有图书多少本．
<gadget id="calculator">90 / 3</gadget>
<output>30</output>

<gadget id="calculator">30 - 3</gadget>
<output>27</output>

<gadget id="calculator">27 + 5</gadget>
<output>32</output>

<result>32</result>