Sergey went to school by bicycle. Classes at school begins at 9 o'clock. In 8 h 40 min. it already passed a half of a way. If Sergey continues to drive at the same speed, then will arrive to school in 10 min. prior to the classes. How many minutes did he go to school?

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9 hours - 10 min. = 8 hours 50 min. the 8th hour 50 min. - to 8 hour are 40 min. = 10 min. 10 min. + 10 min. = 20 min. Answer: 20 minutes Sergey went to school. It turns out went 20 minutes
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Answer add