A is 1.5 times as fast as B. A alone can do the work in 20 days. If A and B working together , in how many days will the work be completed?  Choose the correct choice from the following answers:	A) 23	B) 22	C) 12	D) 24	E) 25
A can finish 1 work in 20 days   B can finish 1/1.5 work in 20 days - since A is 1.5 faster than B   This means   B can finish 1 work in 20*1.5= 
<gadget id="calculator">20*1.5</gadget>
<output>30</output>
30 days   Now using the awesome GMAT formula when two machines work together they can finish the job in= AB/ (A+B) = 20*30/(20+30) = 20*30/50= 
<gadget id="calculator">20*30/50</gadget>
<output>12</output>
12 days   So answer is 12
<result>C</result>
A is 1.5 times as fast as B. A alone can do the work in 20 days. If A and B working together , in how many days will the work be completed?