Kolya can clean a court yard from snow in two hours, and his younger brother – in three hours. For what time could they clean the yard together?

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For whole (1) we accept all yard: 1) 1: 2 = 1/2 yards - will be cleaned for 1 h by Kolya 2) 1: 3 = 1/3 yards - the younger brother for 1 Part 3) 1/2 + 1/3 = 3/6 + 2/6 = 5/6 will clean it - will clean together for 1 Part 4) 1: 5/6 = 1 * 6/5 = 6/5 = = 1 h 12 min. - will clean with 1 1/5 of the h the yard together. Kolya's Productivity x/2 performance mladiego brother Kolya x/3 General performance = 1 x/2+x/3=1 3x+2x=6 5x=6 x=6/5=1 1/5 of hour or 1 hour 12 minutes
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Answer add