Some persons can do a piece of work in 12 days. Two times the number of such persons will do half of that work in
Choices
A) 9 B) 8 C) 4 D) 3 E) 1

Rationale: "explanation : let x men can do the in 12 days and the required number of days be z more men , less days [ indirect proportion ] less work , less days [ direct proportion ] answer : d ) 3 days"
Answer: D