As per Section 29 of this act, here amount being uncertain, the agreement is void.

Void Agreement

Explanation:
A void agreement is an agreement that is not enforceable by law and has no legal effect. It is essentially treated as if it never existed. In the given scenario, A agrees to sell his car to B at a price which B may be able to pay. This agreement is considered void for several reasons.

1. Uncertain Consideration:
The agreement lacks certainty in terms of consideration. Consideration refers to something of value exchanged between parties in a contract. In this case, the price at which B may be able to pay for the car is uncertain. The lack of a definite and ascertainable price makes the agreement void.

2. Essential Terms Missing:
A valid agreement must contain all the essential elements required by law. These elements include offer, acceptance, consideration, capacity, and intention to create legal relations. In the given scenario, the price at which the car is to be sold is not clearly defined. This missing essential term renders the agreement void.

3. Absence of Legal Intent:
For an agreement to be valid, both parties must have a genuine intention to create legal relations. In this case, A agrees to sell his car at a price which B may be able to pay. The vague nature of the price suggests that the parties may not have intended to create a legally binding contract. Therefore, the agreement is void.

4. Violation of Legal Provisions:
Certain agreements are deemed void under specific legal provisions. For example, if the agreement involves illegal activities or goes against public policy, it will be considered void. While the given scenario does not mention any illegal activities, the absence of a definite price may raise concerns about the legality of the transaction, further supporting the argument that the agreement is void.

Conclusion:
In conclusion, the agreement between A and B to sell the car at an uncertain price is considered void. The lack of certainty in consideration, missing essential terms, absence of legal intent, and potential violation of legal provisions all contribute to the agreement being void and unenforceable.