The number X is placed somewhere between 9 and 10. That's because 9 squared is 81 and 10 squared is 100.
For this case we have that by definition, the circumference of a circle is given by:

Where:
d: It is the diameter of the circle
They tell us that:

Substituting:

Thus, the circumference of the circle is 55 centimeters.
Answer:
Option B
He practiced for 1 hour and 30 minutes
We develop the ratio between the number of milliliters present in 1 tablespoon and that is,
15 mL: 1 tablespoon
We let x be the number of millileter in 3 tbsp and it can be determined through the equation below.
x = 3 tbsp x (15 mL/ 1 tbsp) = 45 mL
Therefore, there are 45 mL in 3 tbsp.