№640
0
Две трубы наполняют бассейн за 2 часа 55 минут, а одна первая труба наполняет бассейн за 7 часов. За сколько часов наполняет бассейн одна вторая труба?
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Fatal error: Uncaught Error: Call to a member function fetch_object() on boolean in /home/virtwww/w_giatrener-ru_b7b4c9ed/http/goal/Goal.class.php:16 Stack trace: #0 /home/virtwww/w_giatrener-ru_b7b4c9ed/http/subgoal/Subgoal.class.php(215): Goal->__construct(NULL) #1 /home/virtwww/w_giatrener-ru_b7b4c9ed/http/problem/problemview.class.php(199): Subgoal->get_clean_link_to_goal() #2 /home/virtwww/w_giatrener-ru_b7b4c9ed/http/problem/problemview.class.php(85): ProblemView->get_all_subgoals_for_problem() #3 /home/virtwww/w_giatrener-ru_b7b4c9ed/http/problem/Problem.class.php(286): ProblemView->get_pr_info() #4 /home/virtwww/w_giatrener-ru_b7b4c9ed/http/page/page_template.php(465): Problem->show_pr_all() #5 /home/virtwww/w_giatrener-ru_b7b4c9ed/http/problem/problem.php(6): require_once('/home/virtwww/w...') #6 {main} thrown in /home/virtwww/w_giatrener-ru_b7b4c9ed/http/goal/Goal.class.php on line 16