P, Q, and R are 3 points on a straight line. QP = 5 cm, PR = 10 cm and QR = 15 cm. Which of the following is true?
Point P lies between Q and R
Point Q lies between P and R
Point R lies between Q and P
Point P lies exactly in the middle of QR.
We can see that QP + PR = 5 + 10 = 15 cm = QR Therefore, P lies between Q and R.
If P, Q, R are three points on a line and Q lies between P and R, then PR−PQ=______.