Bhagwanti inherited Rs 12000.00. She invested part of it as 10% and the rest at 12%.

At the rate of $10 \%$, let the investment by Bhagwanti be Rs. $x$.

Therefore, at the rate of $12 \%$, the investment will be Rs. $(12000-\mathrm{x})$.

At the rate of $10 \%$, her annual income $=\mathrm{x} \times 10 \%$

At the rate of $12 \%$, her annual income $=(12000-\mathrm{x}) \times 12 \%$

So,

$\mathrm{x} \times 0.1+0.12(12000-\mathrm{x})=1280$

or $0.1 \mathrm{x}-0.12 \mathrm{x}=1280-1440$

or $0.02 \mathrm{x}=160$

or $\mathrm{x}=8000$

Thus, at the rate of $10 \%$, she invested Rs. 8000 and at the rate of $12 \%$, she invested Rs. $4000(12000-8000)$.