A can do a job in 9 days and B can do it in 27 days. A and B working together will finish twice the amount of work in ------- days? Choose the most appropriate option.
A) 22 days  B) 18 days  C) 22 6/2 days  D) 27 days  E) 9 days
1/9 + 1/27= 3/27 = 1/9   9/1= 
<gadget id="calculator">9/1</gadget>
<output>9</output>
9*2= 
<gadget id="calculator">9*2</gadget>
<output>18</output>
18 days   Answer: 18 days
<result>B</result>
A can do a job in 9 days and B can do it in 27 days. A and B working together will finish twice the amount of work in ------- days?