Unit 8 · Rates and Ratios
Same Speed, Half the Time — When Do They Finish?
Lesson 7 of 7
About this lesson
Romesh takes 40 minutes to chop the vegetables alone. Lucinda also takes 40 minutes alone. Working together on Saturday, starting at 8:35 am — when do they finish? The key insight: when two workers have the same individual time, together they take exactly half that time. 40 ÷ 2 = 20 minutes → finish at 8:55 am.
Chapters
Question
In a restaurant, the same amount of vegetables need to be chopped every day.
Romesh chops the vegetables on a Thursday. If he starts at 8:45 am and works as quickly as he can, he finishes at 9:25 am.
Lucinda chops the vegetables on a Friday. If she starts at 8:25 am and works as quickly as she can, she finishes at 9:05 am.
They both chop the vegetables on a Saturday. If they start at 8:35 am and work as quickly as they can, what time will they finish?
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