I need help pleas now

Assuming everyone in the family showers only once a day,time taken by 1 person to shower = 11*60+15= 675 secondstime taken by 5 people = 5*675 = 3,375 stime taken by the family in a week = 7*3,375 =23,625 samount of water used in a week = 23,625/(10*60) = 39.375 = 40 liters