P and Q can complete a work in 40 days and 24 days respectively. P alone started the work and Q joined him after 8 days till the completion of the work. How long did the work last?  Choose the most appropriate option:
A) 5 days  B) 10 days  C) 14 days  D) 20 days  E) 26 days
Explanation :   Work done by P in 1 day = 1/40   Work done by Q in 1 day = 1/24   Work done by P in 8 days = 8 Ã— (1/40) = 1/5   Remaining work = 1 â€“ 1/5 = 4/5   Work done by P and Q in 1 day = 1/40 + 1/24 = 1/15   Number of days P and Q take to complete the remaining work = (4/5) / (1/15)= 
<gadget id="calculator">(4/5) / (1/15)</gadget>
<output>12</output>
12   Total days= 8 + 12= 
<gadget id="calculator">8 + 12</gadget>
<output>20</output>
20   Answer : Option 20 days
<result>D</result>
P and Q can complete a work in 40 days and 24 days respectively. P alone started the work and Q joined him after 8 days till the completion of the work. How long did the work last?