A man, a woman or a boy can do a job in 20 days, 30 days or 60 days respectively. How many boys must assist 2 men and 8 women to do the work in 2 days?	Choose the most appropriate option: A) 15 boys B) 8 boys C) 10 boys D) 11 boys E) None of these
Man’s two day’s work = 2 × 1⁄20 th work = 1⁄10 th work   Woman’s two days’s work   = 2 × 1⁄30 th work = 1⁄15 th work   Boy’s two day’s work = 2 × 1⁄60 th work = 1⁄30 th work   Now, let 2 men, 8 women and x boys can complete work in 2 days. Then ,   2 men’s work + 8 women’s work + x boy’s work = 1   2(1⁄10) + 8(1⁄15) + x(1⁄30) = 1   ⇒ x = (1 - 1⁄5 - 8⁄15) × 30 ⇒ x = 8 boys   Answer 8 boys
<result>B</result>
A man, a woman or a boy can do a job in 20 days, 30 days or 60 days respectively. How many boys must assist 2 men and 8 women to do the work in 2 days?