there are three blanks that need answers! The tables show the proportional relationship between two quantities. Write the constant of proportionality for each table.

A table showing pairs of shoes, X, and cost in dollars, Y. 1 pair costs sixty-five dollars. 2 pairs cost one hundred thirty dollars. 3 pairs cost one hundred ninety-five dollars. 4 pairs cost two hundred sixty dollars. A table showing number of hours, X, and distance traveled in miles, Y. After 1 hour, fifty miles were traveled. After 2 hours, one hundred miles. After 3 hours, one hundred fifty miles. After 4 hours, two hundred miles. A table showing the number of feet, X, and the number of inches, Y. 2 feet is twenty-four inches. 4 feet is forty-eight inches. 6 feet is seventy-two inches. 8 feet is ninety-six inches.
(A) The constant of proportionality is
.

(B) The constant of proportionality is
.

(C) The constant of proportionality is
.