Xiao Wang deposited 20,000 yuan in the bank for 2 years. At maturity, Xiao Wang withdrew 20,700 yuan. Excluding interest tax, what is the two-year interest rate?

Interest = principal and interest and-principal.

=207000-20000=700

Interest = principal * interest rate * time

Interest rate = interest/(principal * time) =700/(20000*2)=3.5%