0 reads0 ratings0 helpful
If the prime factorisation of (420) is (2^2\times3\times5\times7), how many even factors does (420) have?
Advertisement
Answer and explanation
Correct answer: (16)
Step 1: An even factor must contain at least one (2). Step 2: Power of (2) has (2) choices, (1) or (2); each of (3,5,7) has (2) choices. Total (=16). Step 3: For even factors, exclude the case (2^0).
Frequently asked questions
What is the correct answer to this question?
(16)
Why is this the correct answer?
Step 1: An even factor must contain at least one (2). Step 2: Power of (2) has (2) choices, (1) or (2); each of (3,5,7) has (2) choices. Total (=16). Step 3: For even factors, exclude the case (2^0).
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Real Numbers. Topic: Prime Factorisation.
Student feedback
Was this question useful?
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Difficulty
Easy0%
Medium0%
Hard0%
Was the explanation clear?
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
Advertisement