To convert the fraction \( \frac{45}{50} \) to a percent, the most straightforward method is to divide the numerator by the denominator and then multiply by 100.
However, given the options provided:
- Divide the numerator and denominator of the fraction by 2.
- Subtract 40 from the numerator and denominator of the fraction.
- Multiply the numerator and the denominator of the fraction by 2.
- Add 50 to the numerator and denominator of the fraction.
The best option is to divide the numerator and denominator of the fraction by 2. This simplifies the fraction to \( \frac{45 \div 2}{50 \div 2} = \frac{22.5}{25} \).
Although this method does simplify the fraction, it does not directly convert it to a percent. The most effective approach is to stick to dividing \( 45 \) by \( 50 \) and then multiplying by \( 100 \), which gives \( 90% \).
In conclusion, while the other methods do not lead directly to a percent, dividing by 2 simplifies the fraction, making it simpler to compute the division afterward. So, if he is to pick an option, he should divide the numerator and denominator of the fraction by 2.