When their child was born, her parents invested $40,000 in a plan guaranteed to increase by 3% per year. The logarithmic function y equals 77.9 log start fraction x over 40,000 end fraction can be used to determine the number of years, y, it takes for the investment to be worth x dollars.

After how many years will the investment be worth approximately 75% more than it was originally and how old will their child be when the investment is worth about $80,000?

The investment is worth approximately 75% more after 19 years, and the investment is worth $80,000 when their child is about 23

Question

When their child was born, her parents invested $40,000 in a plan guaranteed to increase by 3% per year. The logarithmic function y equals 77.9 log start fraction x over 40,000 end fraction can be used to determine the number of years, y, it takes for the investment to be worth x dollars.

After how many years will the investment be worth approximately 75% more than it was originally and how old will their child be when the investment is worth about $80,000?

 The investment is worth approximately 75% more after 19 years, and the investment is worth $80,000 when their child is about 23