Explanation:

- Rini mixed two colors, C1 and C2, in the ratio of 2:3.

- Price per unit of C1 is RS.500.

- She is selling the mixture at RS.650 per unit, which is the breakeven point.

- Breakeven implies the cost of the mixture equals the selling price.

- Let's calculate the cost per unit of the mixture:

- Cost of C1 = 2 units × RS.500/unit = RS.1000

- Let the rate of C2 be X RS/unit.

- Cost of C2 = 3 units × X RS/unit = 3X RS

- Total cost of 5 units (2 units C1 + 3 units C2) = RS.1000 + 3X

- Cost per unit of the mixture = (RS.1000 + 3X) / 5 = RS.650

- Solving: RS.1000 + 3X = 3250, so 3X = 2250, and X = RS.750.

- Therefore, the rate per unit of C2 is Option 1: RS.750