A can do a piece of work in 21 days and B in 28 days. Together they started the work and B left after 4 days. In how many days can A alone do the remaining work?	Choose the correct answer:	A) 33	B) 276	C) 27	D) 14	E) 66
Let A worked for x days.   x/21 + 4/28 = 1 =&gt; x/21 = 6/7 =&gt; x = 18   A worked for 18 days. So, A can complete the remaining work in   18 - 4= 
<gadget id="calculator">  18 - 4</gadget>
<output>14</output>
14 days.   Answer: 14
<result>D</result>
A can do a piece of work in 21 days and B in 28 days. Together they started the work and B left after 4 days. In how many days can A alone do the remaining work?