Let \[ A = \begin{bmatrix} 1 & 1 & 1 \\ 1 & 3 & 1 \\ -2 & -3 & -3 \end{bmatrix}, \quad b = \begin{bmatrix} b_1 \\ b_2 \\ b_3 \end{bmatrix}. \] For \( Ax = b \) to be solvable, which one of the following options is the correct condition on \( b_1, b_2, \) and \( b_3 \)?
The annual profit of a company depends on its annual marketing expenditure. The information of preceding 3 years' annual profit and marketing expenditure is given in the table. Based on linear regression, the estimated profit (in units) of the 4superscript{th year at a marketing expenditure of 5 units is ............ (Rounded off to two decimal places)} 
Which model is represented by the following graph?

The following graph represents:
| List-I (Principle of Extension) | List-II (Description) |
|---|---|
| A. Principle of democratic approach | I. Extension helps people to help themselves. Good extension work is directed towards assisting people to work out their own problems, rather than giving them ready-made solutions |
| B. The grassroots principle of organization | II. People, groups and their conditions differ from place to place. Therefore, extension programmes should be flexible, so that necessary changes can be made whenever needed to meet varying conditions |
| C. Principle of adaptability | III. Participation of people in extension activities is voluntary and development interventions are carried out based on the perceived needs of the people |
| D. Principle of participation | IV. Any development programme should fit in with the local conditions |