How many elements are in P={x: x is a positive multiple of 18 and x<70}?
Answer and explanation
Correct answer: 3
List the positive multiples of 18 in increasing order: 18, 36, 54, 72, and so on. The inequality x<70 includes 18, 36, and 54, but excludes 72 because it is greater than 70. Thus P={18,36,54}, and its cardinality is n(P)=3. Option B would incorrectly include 72, while C and D count numbers that do not satisfy the condition. Therefore option A is correct.
Frequently asked questions
What is the correct answer to this question?
3
Why is this the correct answer?
List the positive multiples of 18 in increasing order: 18, 36, 54, 72, and so on. The inequality x<70 includes 18, 36, and 54, but excludes 72 because it is greater than 70. Thus P={18,36,54}, and its cardinality is n(P)=3. Option B would incorrectly include 72, while C and D count numbers that do not satisfy the condition. Therefore option A is correct.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Common Questions.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
