Out of the choices, the entities with only one dimension and have infinite length are the line and ray. The line extends to both sides while the ray is restricted by an endpoint on one side but can extend infinitely to the other side. The answers are therefore letter D and F.
So .. in 1foot, there are 12inches... thus, in 15feet, there are 15*12 inches
how many in 3/4 of an inch? well

solve for "x"
Add 6 7 and two you get 15 xy subtract -11 and -4 you get positive 7xy add 15 and 7 and you get 22xy