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The gifts that Coach Hardy ordered for his students had just been delivered to his house. Given the large number of students, if he were to pack the gifts himself, itwould take him 3 hours! Fortunately, one hour into packing, his son Timothy was done with homework and offered to help. To Hardy’s surprise, Timothy could do it twice as fast as himself!Together they finished packing all gifts. For how long (in minutes) did Timothy help Hardy?

 Jan 11, 2021
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Tim can do it twice as fast as hardy- this means when both are working together the total is 3x hardy's speed. 

 

After 1/3 of packing is done, tim comes to help.

 

it would take 2 hours normally to pack the remaining 2/3 but at 3x the speed it takes 2/3 HOURS instead of 2 hours, so only 40 minutes?

 

Alone, it would take 40x3 + 60 = 180, 3 hours for hardy alone. Let me know if anything is errorous.

 Jan 11, 2021

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