If 8 men or 12 women can do a piece of work in 35 days, in how many days can the same work be done by 6 men and 11 women?  Pick.
A) 10 days  B) 11 days  C) 13 days  D) 15 days  E) 21 days

Rationale: "8 men = 12 women ( i . e 2 men = 3 women ) 12 women 1 day work = 1 / 35 soln : 6 men ( 9 women ) + 11 women = 20 women = ? 1 women 1 day work = 12 * 35 = 1 / 420 so , 20 women work = 20 / 420 = 1 / 21 ans : 21 days answer : e"
Answer: E