Lizzy: Jim starts with $80 in his investment portfolio. After 1 year it grows by 15%. He then adds another $28 to his portfolio. After 1 more year the combined portfolio grows by 10%. What is his final portfolio worth after 2 years from when he started?.
Me: Hmmm, let me think. I think this is the detailed solution:
After 1 year Jim has gained $80 * 0.15 = $12. Therefore, after 1 year his portfolio has grown to $80 + $12 = $92. He then adds $28 to this total, so his new portfolio total is $92 + $28 = $120 at the beginning of year 2. Next, this total grows by 10%, so he gains $120 * 0.10 = $12 across year 2. Thus, after year 2, his portfolio is worth $120 + $12 = $132. Final answer: 132.