3 men, 4 women and 6 children can complete a work in 7 days. A woman does double the work a man does and a child does half the work a man does. How many women alone can complete this work in 7 days? Choose the correct option:
A) 7
B) 8
C) 6
D) 5
E) 3
Let 1 woman's 1 day work = x.   Then, 1 man's 1 day work = x/2 and 1 child's 1 day work x/4.   So, (3x/2 + 4x + + 6x/4) = 1/7   28x/4 = 1/7 =&gt; x = 1/49   1 woman alone can complete the work in 49 days.   So, to complete the work in 7 days, number of women required = 49/7= 
<gadget id="calculator">49/7</gadget>
<output>7</output>
7.   7nswer: 7
<result>A</result>
3 men, 4 women and 6 children can complete a work in 7 days. A woman does double the work a man does and a child does half the work a man does. How many women alone can complete this work in 7 days?