Garden City Beach is a popular summer vacation destination for thousands of people. Each summer, the city hires temporary lifeguards to ensure the safety of the vacationing public. Garden City's lifeguards are assigned to work five consecutive days each week and then have two days off. However, the city's insurance company requires them to have at least the following number of lifeguards on duty each day of the week. Lifeguards Minimum Number of Lifeguards Required Each Day Sunday Monday Tuesday Wednesday Thursday Friday Saturday 18 17 16 16 16 15 19 The city manager would like to determine the minimum number of lifeguards that will have to be hired. (a) Formulate an ILP for this problem. (Let X be the number of lifeguards whose shift starts on Sunday, X2 be the number of lifeguards whose shift starts on Monday, ..., and X, be the number of lifeguards whose shift starts on Saturday.) MIN: Subject to: Sunday constraint Monday constraint X + X 2 + X3+ X 4 + X5 + X6 + X7 X+0X+ QX3+X+X+X+X 18 X+X+0X3+0X+X5 +X+X 17 6 Tuesday constraint X+X+Xz + QX+0X+X+X 16 Wednesday constraint X+X+X+X+0X+0X+X 16 6 Thursday constraint X+X+X+X+X+0X6+0X7 16