Question

Points!!!!!!!!!!!!!

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?
A.) 120
B.) 40
C.) 24
D.) 20

Answer 1

if they are working together well it already takes jannette 60 minutes and liza is 20 minutes faster since Liza is the faster one you would use her time and that would be 60 - 20 = 40 so B

Answer 2

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