A can do a job in 15 days and B can do it in 30 days. A and B working together will finish twice the amount of work in ------- days?
Choose the correct choice from the following answers.
A) 14 days	B) 16 days	C) 20 days	D) 11 days	E) 19 days
20 days   1/15 + 1/30 = 1/10   10*2= 
<gadget id="calculator">10*2</gadget>
<output>20</output>
20 days
<result>C</result>
A can do a job in 15 days and B can do it in 30 days. A and B working together will finish twice the amount of work in ------- days?