A and B can complete a work in 30days and 15day. They started doing the work together but after 5days B had to leave and A alone completed the remaining work. The whole work was completed in? Choose the correct choice from the following
A) 10days B) 12days C) 20days D) 18days E) 25days
A+B 1day work = 1/30 + 1/15 +  1= 
<gadget id="calculator">+  1</gadget>
<output>1</output>
1/30 + 1/15= 1/10   Work done by A and B in 10days = 1/10 * 5 = 1/2   Remaining work = 1-1/2 = 1/2   Now 1/30 work is done by A in 1day   1/2 work will be done by A in 30*1/2= 
<gadget id="calculator">30*1/2</gadget>
<output>15</output>
15days   Total time taken= 15+5= 
<gadget id="calculator">15+5</gadget>
<output>20</output>
20days   Answer is 20days
<result>C</result>
A and B can complete a work in 30days and 15day. They started doing the work together but after 5days B had to leave and A alone completed the remaining work. The whole work was completed in?