When \(\frac{3}{2^4\cdot 5^6}\) is written as \(\frac{N}{10^6}\), what is \(N\)?
Answer and explanation
Correct answer: 12
Since \(10^6=2^6\cdot5^6\), compare this with the given denominator \(2^4\cdot5^6\): the factor \(2^2\) is missing. Multiply numerator and denominator by \(2^2=4\) to obtain denominator \(10^6\), so \(N=3\times4=12\). The distractor 24 would result from mistakenly multiplying by \(2^3=8\). Exam tip: to express a fraction with denominator \(10^n\), match the prime powers of 2 and 5 in the denominator to exponent \(n\).
Frequently asked questions
What is the correct answer to this question?
12
Why is this the correct answer?
Since \(10^6=2^6\cdot5^6\), compare this with the given denominator \(2^4\cdot5^6\): the factor \(2^2\) is missing. Multiply numerator and denominator by \(2^2=4\) to obtain denominator \(10^6\), so \(N=3\times4=12\). The distractor 24 would result from mistakenly multiplying by \(2^3=8\). Exam tip: to express a fraction with denominator \(10^n\), match the prime powers of 2 and 5 in the denominator to exponent \(n\).
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Real Numbers. Topic: Decimal expansion of rational numbers.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
