How do you do these questions? The first two questions could have multiple answers and the third is one answer only.

1. c is the correct option, a and b are false

2. It is always desirable that all the object instance variables contribute to calculating the hash code.

3..( getfirstname +getSecondName).Hashcode()

Explanation:

1. Two same hashcode cannot be in same hashset, and if two keys are equal then it does not mean, their hash code should also be equal. And if a key is greater, then its hashcode will definitely be greater.

2. Each object instance variable must contribute to calculating the hash code, as we need one hash code for each key or object. However, set.Contains(Obj) must return true if we have a hash code for that object, as it must be present in HashSet then.

3. Also for each of the key we need one hash code, and here the first name and the last name together are making one key, and hence we should concatenate both, and then generate a hash code for that concatenated key, and hence the correct option is (getFirstName + getSecondName).Hashcode()

we can all learn from our past mistakes because we all have different ways of learning different types of techniques. my way may or may not another classmate remember and have the repetition to acknowledge such standard. such as remembering acronyms. using abbreviations to us remember keep things in order in our memory. this us figure out what comes next in the sequence. if so, what we have is a sentence of just letters all in caps. we either know the meaning or have no idea what it stands for. most of the time we know the meaning and context. but most of us who don't know, should learn by having a quick glance at what needs to be remembered. such as repetition in the memory for acronyms. one way that me, is the fact that i'm always doing math and english assignments. so we have to remember specific meanings such as soapstone for documents, such as citing correctly. or pemdas for doing the equations correctly, even if it's the super long way. this works for everyone. you just have to find what works for you by practicing and repetition daily.