Later, shelf A added 38 books, and shelf B lent 72 books.

Then A is 38+72 more than B =110.

At this time, there are three times as many books on shelf A as on shelf B, so

A is more than B 1 10, which is twice as much as B.

B At this time,11(3-1) = 55 copies.

So two shelves have 55+72= 127 books.