A can finish a work in 12days, B in 9days and C in 2days, B and C start the work but are forced to leave after 3 days. The remaining work was done by A in? Choose the most appropriate option
A) 10days
B) 12days
C) 6days
D) 7days
E) 5days
B+C 1day work = 1/9 + 1/12 +  1= 
<gadget id="calculator">+  1</gadget>
<output>1</output>
1/9 + 1/12= 7/36   work done by B and C in 3days = 7/36 * 3 = 7/12   Remaining work = 1 - 7/12 = 5/12   1/24 work is done by A in 1day   5/12 work is done by A in  12*5/12= 
<gadget id="calculator"> 12*5/12</gadget>
<output>5</output>
5days   Answer is 5days
<result>E</result>
A can finish a work in 12days, B in 9days and C in 2days, B and C start the work but are forced to leave after 3 days. The remaining work was done by A in?