What is the roster form of P = {x : x is a number from 1 to 100 whose last digit is 2}?
Answer and explanation
Correct answer: P = {2, 12, 22, 32, 42, 52, 62, 72, 82, 92}
A number whose last digit is 2 appears in the sequence 2, 12, 22, 32, and so on, increasing by 10 each time. Restricting the numbers to the interval from 1 through 100 gives 2, 12, 22, 32, 42, 52, 62, 72, 82, and 92. The number 102 is not allowed because it exceeds 100. Therefore, option A is the complete roster form of P.
Frequently asked questions
What is the correct answer to this question?
P = {2, 12, 22, 32, 42, 52, 62, 72, 82, 92}
Why is this the correct answer?
A number whose last digit is 2 appears in the sequence 2, 12, 22, 32, and so on, increasing by 10 each time. Restricting the numbers to the interval from 1 through 100 gives 2, 12, 22, 32, 42, 52, 62, 72, 82, and 92. The number 102 is not allowed because it exceeds 100. Therefore, option A is the complete roster form of P.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
