Jamie and owen joined a monthly walking challenge at their youth center. jamie has already walked 120 minutes and plans to walk 20 minutes per day. owen plans to walk 30 minutes per day. let x represent the number of days and y represent the total number of minutes walked during the challenge. which system of equations can be used to find the number of days it will take for owen and jamie to have walked the same number of minutes?

a) y= 20x + 120
y= 30x

b) y= 20x
y= 30x + 120

c) y= 120x + 20
y= 30x

d) y= 120x
y= 30x + 20