1. Is there an enforceable contract between Samantha and Julie?
2. Assuming there is an enforceable contract between Julie and Samantha, does Samantha need to pay $100 to Julie’s mother Martha?
3. Is promissory estoppel relevant to Samantha’s dispute with Dave from ‘Outrageous Costumes’?
4. Is Will entitled to two free tickets for helping set up for the school play?
1. Enforceable Contract between Samantha and Julie
The main issue is related to find the existence of an enforceable contract between Samantha and Julie.
An enforceable contract refers to the contract which is recognized as valid by the courts and subject to the ability of the court to ensure compliance with its items. A contract must consists of an offer, consideration, and acceptance to be legally valid and enforceable. In addition, it can also be stated that if a contract lacks any of these elements, it is not an enforceable contract. Bressan v Squires requires to this situation, which states the importance of having consideration, offer, and acceptance elements to make a contract enforceable..
On the basis of above definitions of an enforceable contract, it can be discussed that there is an enforceable contract between Samantha and Julie. It is because the contract between them includes specific components, which make it legally enforceable.
Offer: An offer refers to a proposal made by a person to do a task or to pay an amount if the work is accepted. It makes a contract legally valid. In the given case, Samantha makes a proposal to Julie to prepare cakes and sandwiches for 100 people and Julie accepts this proposal by stating that "Yes I can and I will need one weeks’ notice and the price/charge will be $5 per person, so $500 in total".
Acceptance: Another component is acceptance, which is related with an unconditional agreement to the exact terms and conditions of the offer. The given case also contains this component because Julie accepts the proposal without any extra condition to the terms made by Samantha in the offer.
Consideration: It is also essential to make an enforceable contract that the payment must be exchanged for the promises comprised in a contract. This component also exists in the given case as Julie says Samantha that she will charge $5 per person or there will a $500 consideration in total. Samantha accepts this proposal and sends a text message on Julie's phone.
Thus, it can be concluded that as in the contract, there are all the essential elements such as legal consideration, proper offer and acceptance, the contract between Samantha and Julie is enforceable.
2. Samantha Vs Julie's Mother
It is found from the case that ingredients for preparing cakes and sandwiches are used by Julie from her parents' household fridge and cupboard. Julie refuses to make a payment to her mother when she asks to pay her back for the ingredients. As a result, Julie's mother, Martha directly contacts Samantha and says that you need to give me $100 as Julie has used all my ingredients to prepare sandwiches and cakes. Martha says to adjust this amount out of the Julie's $500 in order to pay back for the expense incurred. The issue is that by assuming that 'there is an enforceable contract between Julie and Samantha, does Samantha need to pay $100 to Julie’s mother Martha'.
As given in the case of "Australian Woollen Mills Pty Ltd v The Commonwealth", the courts recognize an enforceable contract valid, and thus, it is essential for the contract parties to make sure about the compliance with all terms and conditions. It is assumed that there is an enforceable contract between Julie and Samantha and due to this, both Julie and Samantha has obligations to perform their tasks as per the contract. For example, Samantha will make a payment of $500 to Julie and Julie will provide cakes and sandwiches for 100 people.
As the contract is enforceable, Samantha is obliged towards Julie and make her payment as $500. In case, if she makes payment of $100 to Julie's mother and remaining $400 to Julie, it may result in the breach of the contract. It is because the enforceable contract exist between Samantha and Julie and Julie can sue Samantha for this. Thus, there is no need for Samantha to pay $100 to Julie's mother Martha as it is the duty of Julie to make payment to her mother to pay back for the ingredients used. However, Samantha can guide Julie to pay to her mother as she also needs to pay back for the ingredients to the third party.
Thus, it can be concluded that Samantha does not require to pay the mother of Julie.
3. Relevancy of promissory estoppel to Samantha’s dispute with Dave from ‘Outrageous Costumes’
The main problem is to identify that whether 'promissory estoppel is relevant for the dispute between Samantha and Dave from ‘Outrageous Costumes’'.
The courts of equity originally established the doctrine Promissory Estoppel. In some case, in which an individual reasonably believes that he/she has entered into a contract, the doctrine of promissory estoppel arises. Based on this reasonable opinion that there is a contract, the promisee changes his position materially. This situation occurs when the promise made by the likely offeror is illusory or when the promise cannot be fixed objectively. The law does not allow a promisee to suffer, if it can be demonstrated that the promisee has changed his/her position materially in reasonable reliance on the promise. It will be the obligation for the promisor to compensate the promisee. It shows that the promisor is estopped through this doctrine 'from avoiding a promise because to do so would be unjust to the promise'.
To determine the existence of Promissory estoppel, it is essential to show that the promisee detrimentally relied on the promise, and that the offeror never meant to give a gift to the promisee.
The case applicable to this situation is "Central London Property v High Trees", in which landlord P promised to reduce rent for D. But, due to changes in circumstances after war, he did not reduce the rent. 
In the given case, Samantha mailed to Dave to prepare three Smurf space suits, with extra silver and blue. Dave e-mailed back to Samantha about his requirement to know the costumes size. Dave also writes ‘Silver and Blue material is extra expensive. I rarely use it and will have to order it in specially’. By knowing this, Samantha replies at once and says ‘please go ahead and order the material – I will provide the measurements the week before the production’. In addition, she also writes in the mail that ‘we don’t have much time to get this all organised’. It shows that Samantha promises to design costumes by using the material. On the basis of this promise, Dave ordered the material and after receiving the material, he informed Samantha about starting of making the costumes. After receiving the message, Samantha ignores it as a parent offered to provide the costumes for free. Before two days the school production, Samantha informs Dave to cancel the order, but at that time, Dave has nearly to complete the costumes, which he would not be able to reuse.
However, there is no mutuality of offer because Samantha did not ordered to design the costumes after receiving the material by Dave. She simply promised to buy the material so that Dave can start the work as early as possible because they have lack of time.
It shows that the doctrine promissory estoppel is relevant to Samantha’s dispute with Dave from ‘Outrageous Costumes’. It is because Dave started the making of costumes after receiving the material as well as informed about in this concern to Samantha based on her promise. Thus, he can sue Samantha under this doctrine to recover his payment for the material and the designing of the costumes. Although the court will not give him the full payment, however will compensate him for his actual loss based on her promise.
Thus, it can be concluded that promissory estoppel is relevant to 'Samantha’s dispute with Dave from ‘Outrageous Costumes’'.
4. Evaluation of Will's Entitling to the Free Tickets
The issue is as Will is amongst the first 10 parent, whether he is entitled to two free tickets offered by Samantha for helping in making arrangements for the school play.
Between Will and Samantha, there is a contract, but this is not enforceable because it lacks the main elements of the contract.  The case, "Carlill v Carbolic Smoke Ball Co" applies to this event. In this case, the contract was valid as a unilateral contract comprising a valid offer and acceptance. 
Thus, it shows that there is an unilateral contract between Samantha and Will. As Samantha made a offer by sending an email stating requirements of some volunteers to help in making arrangements for the play to all the parents. She also says that ' The first 10 parents to arrive at 12.00 pm today to assist with the set up will receive two free tickets to tonight’s performance.’ In addition, there is also the acceptance of the contract by Will as he performed conditions stated in the offer by Samantha. For instance, Will sees the email and with the expectation to watch the play, he determines to work as a volunteer. As given in the case, 'Will is amongst the first 10 people to arrive and assists with the setup of the play'. It is assumed that Will plays the role of guardian for his younger brother regarding this play. Thus, it shows that Will is entitled to two free tickets as he assisted Samantha to set up for the school play. It is because he fulfill all the requirements of the promise made by Samantha to offer two free tickets.
It can be concluded that Will is eligible to get two free tickets from Samantha.
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