It takes Avery 2.5 hours to build a brick wall while Tom can do it in 5 hours. If the two start working together and after an hour Avery leaves, how much time will it take Tom to complete the wall on his own? Pick one: A) 15 minutes. B) 30 minutes. C) 1 hour and 30 minutes. D) 1 hour and 40 minutes E) 2 hours
Avery's efficiency is 100/2.5= 
<gadget id="calculator">100/2.5</gadget>
<output>40</output>
40%   Tom's= 100/5= 
<gadget id="calculator">100/5</gadget>
<output>20</output>
20%   they worked together for 1 hour and finished 60 % of the job   remaining= 40 %   Tom will complete 20% in 60 minutes , 40% in 120 minutes   Time taken by Tom to finish the remaining on his own = 120 minutes   ANSW2 hoursR:2 hours
<result>E</result>
It takes Avery 2.5 hours to build a brick wall while Tom can do it in 5 hours. If the two start working together and after an hour Avery leaves, how much time will it take Tom to complete the wall on his own?