C. Solve the following problems:
1. How much will I gain if I invest my 350,000 for years at \( 7 \% \) simple interest?
2. After I deposited \( 尹 500,000 \) In a time deposit were the bank offered \( 5 \% \) rate of simple interest, I got \( P 550,000 \). How long did it take me to get my money?