An inchworm (exactly one inch long, of course) is crawling up a yardstick (guess how long that is?). After the rst day, the inchworm's head (let's just assume that's at the front) is at the 3" mark. After the second day, the inchworm's head is at the 6" mark. After the third day, the inchworm's head is at the 9" mark. Let d equal the number of days the worm has been crawling. (So after the rst day, d = 1.) Let h be the number of inches the head has gone. Let t be the position of the worm's tail.