1. **State the problem:** Simon invests 5000 at 5% interest compounded semi-annually. After 3 years, he withdraws 3000. Find the amount left after 5 years. 2. **Formula for compound interest:** $$A = P \left(1 + \frac{r}{n}\right)^{nt}$$ where $A$ is the amount, $P$ is the principal, $r$ is the annual interest rate (decimal), $n$ is the number of compounding periods per year, and $t$ is time in years. 3. **Calculate amount after 3 years before withdrawal:** Given $P=5000$, $r=0.05$, $n=2$ (semi-annual), $t=3$, $$A_3 = 5000 \left(1 + \frac{0.05}{2}\right)^{2 \times 3} = 5000 \left(1.025\right)^6$$ Calculate $1.025^6$: $$1.025^6 \approx 1.15969$$ So, $$A_3 = 5000 \times 1.15969 = 5798.45$$ 4. **Withdraw 3000 after 3 years:** $$A_{after\ withdrawal} = 5798.45 - 3000 = 2798.45$$ 5. **Calculate amount after 2 more years (total 5 years) with new principal:** Now $P=2798.45$, $t=2$, $$A_5 = 2798.45 \left(1 + \frac{0.05}{2}\right)^{2 \times 2} = 2798.45 \times 1.025^4$$ Calculate $1.025^4$: $$1.025^4 \approx 1.10381$$ So, $$A_5 = 2798.45 \times 1.10381 = 3088.88$$ 6. **Final answer:** The amount left in the account after 5 years is approximately **3088.88**.