There is a bookcase. There are 285 books on the upper, middle and lower floors. Take 11 books from the upper floor to the lower floor. After taking (1/5) books from the middle floor, the number of books on the upper floor is the same as that on the middle floor, occupying the lower floor respectively. (2/3) of the number of books, then how many books are there in the upper layer.
有一个书柜，上、中、下三层共放有285册书，从上层拿11本到下层，从中层拿走(1/5)的书后，上层的册数与中层一样多，分别占下层册数的(2/3)，那么原来上层有多少册书．
<result>87</result>