Answer:
Author D write 1/16 of the total number of books.
Step-by-step explanation:
Let the total number of books be b. Then the amounts written by the four authors would be represented by:
(1/4)A
(5/16)A
(3/8)A
( ? )A
Add these together, realizing that the LCD here is 16:
(4/16)A
(5/16)A
(6/16)A
( ? ) A
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(15/16)A must then equal the remainder of the work: (16/16)A
Thus, Author D wrote (1/16)A of the books. (Note that 4/16 + 5/16 + 6/16 + 1/16 = 1)
Author D write 1/16 of the total number of books.