I believe the correct answer is the second option. A system having three linear equations which has 3 variables, consistent and independent will only have one solution. A consistent would have at least one solution. An independent one would have exactly one.
45(5)=225 than multiply that by 60 because remember he only swam 5 out of 7 days a week (12x5=60) therefore 225x60= 13,500 minutes to convert to hours divide by 60 which will be 225 hours