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. (a) Formulate an ILP for this problem. (Let X1 be the number of lifeguards whose shift starts on Sunday, X2 be the number of lifeguards whose shift starts on Monday, ... and x7 be the number of lifeguards whose shift starts on Saturday.) (b) Implement your model in a spreadsheet and solve it. What is the optimal solution? (x1,x2,x3,x4,x5,x6,x7)=( increasing the total number of life guards required? lifeguard(s) 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. (a) Formulate an ILP for this problem. (Let X1 be the number of lifeguards whose shift starts on Sunday, X2 be the number of lifeguards whose shift starts on Monday, ... and x7 be the number of lifeguards whose shift starts on Saturday.) (b) Implement your model in a spreadsheet and solve it. What is the optimal solution? (x1,x2,x3,x4,x5,x6,x7)=( increasing the total number of life guards required? lifeguard(s)