75% is written as 0.75 as a decimal or 3/4 as a fraction.
Her friends take 75% longer, so multiply the time it takes Ashley by 1 + the percentage: 1.75 as a decimal or 1 3/4 (7/4) as a fraction.
2/3 x 7/4 =14/12 = 1 2/12 = 1 1/6 minutes.
1 hour = 60 minutes.
Divide minutes in an hour by inutes per pack:
Ashley can pack: 60 / 2/3 = 90 bags per hour
1 friend can pack: 60 / 1 1/6 = 51 3/7 bags per hour.
multiply the amount 1 friend can pack by 4 friends: 51 3/7 x 4 = 205 5/7 bags per hour.
Ashley and her friends can pack 90 + 205 5/7 = 295 5/7 bags per hour.
Now divide the total bags by bags per hour:
1575 / 295 5/7 = 5.33 hours ( Round answer as needed.)