Todays typical hip implant weighs about 50% less than it did 20 years ago. if an implant weighs about 3lb today how much did it weigh 20 years ago?

If todays hip implant weighed about 50% less then it did 20 years ago, that means that 20 years ago, it weighs 50% more then it does today.

so if it weighs 3 lb today, then 20 years ago it weighed:

3 + 0.5 (3) = 3 + 1.5 = 4.5 lbs <==

150 is the answer to the problem