A car wheel having a radius of 42 cm. What percentage of its circumference is covered in a half turn? (Use $\pi =\frac{22}{7}$)

The correct option is 50%.

Step-by-Step Explanation:

1. Understand the concept of circumference and turn of a wheel:
The circumference of a circle represents the distance covered by a wheel in one complete turn (1 full rotation or 360°).

2. Calculate the fraction of circumference covered in a half turn:
A half turn corresponds to half of a complete rotation (1/2 or 50% of 360°).

Therefore, the fraction of the circumference covered in a half turn is:

$\text{Fraction covered}=\frac{1}{2}$

3. Convert the fraction to a percentage:
To express this fraction as a percentage, multiply by 100:

$\text{Percentage covered}=(\frac{1}{2}\times 100)\%=50\%$

Thus, exactly 50% of the circumference is covered in a half turn.