Jannette can repair a refrigerator in 60 minutes. Liza can repair a refrigerator 20 minutes faster. If they work together, how many minutes does it take them to repair the refrigerator?

Question

ali2x2 · Answer

40 minutes

ali2x2 · Answer

subtract 60 and 20

anonymous · Answer

There isnt a fraction i have to do first?

anonymous · Answer

Assuming that 2 people who will repair a refrigerator equally fast will do it twice as fast when working together:

Jannete repairs 1/60 refrigerator per minute. 
Lisa repairs 1/40 refrigerator per minute.
Togheter they repair 1/60+1/40= 1/60 + 1,5/60 = 2,5/60=5/120=1/24 refrigerator per minute
thus it will take them 24 minutes