A number of books (are) on the table.
Explanation: "A number of" is followed by a plural noun and takes a plural verb.
The number of students in this class (is) limited to thirty.
Explanation: "The number of" is followed by a singular noun and takes a singular verb.
Each boy in this class (has) his own notebook.
Explanation: "Each" is singular and takes a singular verb.
Everybody (has) a good time.
Explanation: "Everybody" is singular and takes a singular verb.
No one (is) eager to be examined.
Explanation: "No one" is singular and takes a singular verb.
Bread and butter (is) all he asked for.
Explanation: When two singular nouns are connected by "and" but referring to one item or concept, it takes a singular verb.
A fever, a loss of wealth, a loss of respect, a loss of friends (seems) at the moment, an old loss.
Explanation: The subject is a list of items connected by "a" and is treated as a singular subject when referring to the concept as a whole.
The boxes of candy (are) correct.
Explanation: "The boxes" is a plural subject and takes a plural verb.
Most of the members (are) happy.
Explanation: "Most" of a plural noun is followed by a plural verb.
Neither of the answers (is) correct.
Explanation: "Neither" is singular and takes a singular verb.
Half of the students (are) looking for.
Explanation: "Half of the students" is plural and takes a plural verb.
Some of the sugar (was) spilled on the floor.
Explanation: "Some" of a mass noun (sugar) takes a singular verb.
The result of Dr. Noll's experiment (was) published in a scientific journal.
Explanation: "The result" is singular and takes a singular verb.
There (is) plenty of time.
Explanation: "There is" used with an uncountable noun like "time" takes a singular verb.