25 binders can bind 1400 books in 21 days. How many binders will be required to bind 1600 books in 20 days?  Choose the most appropriate option:
A) 87
B) 18
C) 17
D) 16
E) 30

Rationale: "binders books days 25 1400 21 x 1600 20 x / 25 = ( 1600 / 1400 ) * ( 21 / 20 ) = > x = 30 answer : e"
Answer: E