A and B can do a work in 4 hours and 12 hours respectively. A starts the work at 6AM and they work alternately for one hour each. When will the work be completed?  Options:
A) 3 days
B) 6 days
C) 7 days
D) 2 days
E) 8 days
B   6 days   Work done by A and B in the first two hours, working alternately = First hour A + Second hour B = 1/4 + 1/12 = 1/3.   Total time required to complete the work = 2 * 3= 
<gadget id="calculator">2 * 3</gadget>
<output>6</output>
6 days.
<result>B</result>
A and B can do a work in 4 hours and 12 hours respectively. A starts the work at 6AM and they work alternately for one hour each. When will the work be completed?