Bunuel
One man can do as much work in one day as a woman can do in 2 days. A child does one third the work in a day as a woman. If an estate-owner hires 39 pairs of hands, men, women and children in the ratio 6 : 5 : 2 and pays them in all $1113 at the end of the days work. What must the daily wages of a child be, if the wages are proportional to the amount of work done?
(A) $5
(B) $7
(C) $14
(D) $14
(E) $20
Are You Up For the Challenge: 700 Level QuestionsComparing efficiencies per day: Efficiency of a man = 2 * Efficiency of a woman
Comparing efficiencies per day: Efficiency of a woman = 3 * Efficiency of a child
Combining: Efficiency of a man = 2 * Efficiency of a woman = 6 * Efficiency of a child
Assuming that a child does 1 unit work per day: Work done by a woman per day = 3 units; Work done by a man per day = 6 units
Ratio of men, women and children = 6 : 5 : 2
=> Work done per day is proportional to 6*6 + 5*3 + 2*1 = 53 units; which is equivalent to $1113
=> Each unit of work is equivalent to 1113/53 = $21
=> Amount obtained by the children who do equivalent to 2 units of work = $21 x 2 = $42
Since there were 39 people, number of children = 2/(6+5+2) x 39 = 6
Thus, $42 was obtained by 6 children
=> Amount obtained by each child = 42/6 = $7
Answer B