orking together, Jenny and Natalie can mop a warehouse in 5 hours. Had she done it alone it would have taken Natalie 12 hours. How long would it take Jenny to do it alone? Express your answer in hours and minutes to the nearest minute.
+36915 1/j + 1/n = 1/5
1/j + 1/12 = 1/5 solve for 'j' jenny's time alone
1/j = 1/5 - 1/12
1/j = 7/60
j = 60/7 hr
= 8.57 hr = 8 hr 34 min
