Cutting her time by 50% means reducing her time by half. Half of 45 seconds is 22.5 seconds. Therefore, to make the team, she must run a lap in 22.5 seconds.
Imagine what x is quantity of stools. So 3x+120=4x x=120 120 stools in cafeteria 120 chairs in cafeteria 120+120=240 There 240 people can sit in this cafeteria