A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work in 23 days. The number of days after which A left the work was	Choose the correct choice from the following answers.
A) 5 days	B) 6 days	C) 7 days	D) 9 days	E) 8 days
does the job in 40 days = 1/40   A &amp; B together completes the job = ?   After A leaves, B completes the remaining job in 23 days.   i.e B's part of job in 23days = 23/40   Remaining part 17/40 is done by A &amp; B together in x no.of days.   i.e (x/45) + (x/40) = 17/40   =&gt; x = 9 days   ANSWER:9 days
<result>D</result>
A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work in 23 days. The number of days after which A left the work was