60 women can complete a work in 7 days and 10 children take 14 days to complete the work. How many days will 5 women and 10 children take to complete the work?  Choose the correct choice from the following.
A) 8 days B) 6 days C) 7 days D) 9 days E) 12 days

Rationale: "1 women ' s 1 day work = 1 / 420 1 child ' s 1 day work = 1 / 140 ( 5 women + 10 children ) ' s 1 day work = ( 5 / 420 + 10 / 140 ) = 1 / 12 5 women and 10 children will complete the work in 12 days . answer : e"
Answer: E