The school launched a book donation activity for children in mountainous areas. The number of books donated by the fifth grade accounted for (4/15) of the total number of the school, and the number of donated books by the sixth grade accounted for (1/3) of the total number of the school. How many books donated by the two grades account for the total number of books in the school? Please ask a few more math questions and answer them to see who asks more questions?
学校开展为山区小朋友捐书活动．五年级捐书的本数占全校总本数的(4/15)，六年级捐书的本数占全校总本数的(1/3)．两个年级捐的书占全校总本数的几分之几？请你再提出几个数学问题，并把它解答出来，看谁提的问题多？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>