Which of these pairs of quantities are proportional to each other? For the quantities that are proportional, what is the constant of proportionality?
a. Radius and diameter of a circle
b. Radius and circumference of a circle
c. Radius and area of a circle
d. Diameter and circumference of a circle
e. Diameter and area of a circle

Malia is observing the velocity of a cyclist at different times. after two hours, the velocity of the cyclist is 15 km/h. after five hours, the velocity of the cyclist is 12 km/h. part a: write an equation in two variables in the standard form that can be used to describe the velocity of the cyclist at different times. show your work and define the variables used. (5 points) part b: how can you graph the equations obtained in part a for the first 12 hours? (5 points) if you can try and make this as little confusing as you can

Brainlest answer can you find the area and circumference of a circle given the radius or diameter? if its yes or no explain why

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?