Teacher asks one of the student to name the excretory organs in man. He names three organs beside kidney. Teacher appreciates him for the correct answer. What was his answer?

Name three kinds of excretory organs found in invertebrates ?

Is there an organic compound named 2- Ethylpentane? Why? If no, write the correct answer.

Teacher asked the student for a reaction of 2-bromopropane with alcoholic KOH. What is the name of reaction?

In an examination 20 question of true false type are asked suppose a student tosses a fair coin to determine his answer to each question if the coins falls heads he answers true if it falls tail he answers false find the probability thet he answers at least 12 question correctly.

In answering a question on a multiple choice test,a student either knows the answer or guesses. Let 3/4 be the probability that he knows the answer and 1/4 be the probability that he guesses. Assuming that a student who guesses at the answer will be correct with probability 1/4. What is the probability that the studdent knows the answer given that he answered it correctly?