it takes avery 3 hours to build a brick wall while tom can do it in 4 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 ?
"avery ' s efficiency is 100 / 3 = 33 % tom ' s = 100 / 4 = 25 % they worked together for 1 hour and finished 58 % of the job remaining = 42 % tom will complete 25 % in 60 minutes , and 17 % in 60 * 17 / 25 minutes = 40.8 minutes time taken by tom to finish the remaining on his own = 60 + 40.8 = 100.8 minutes ( adjusting for 0.2 ) ~ 101 minutes answer : c"
multiply(divide(subtract(const_1, add(divide(const_1, 3), divide(const_1, 4))), divide(const_1, 4)), const_60)