Kayla plans to swim 2 laps per minute until she swims 12 laps. she figures this will take 1/6 minute. which is not a reason why this conclusion is wrong.

If she can swim 2 laps in one minute, she can swim 1 lap in half the time.  If you set it up as a proportion, it's easy to figure out.  I'm setting up the proportions with laps on top and minutes on bottom: .  Cross multiply to get 2x = 12 and x = 6.  This means that in half the time it takes to swim 2 laps, she can swim half the distance.

50 % is the answer !