Question

If P - Q - R and d(P, Q) = 10 units, d(P, R) = 20 units, then d(Q, R) = ________ units.

• A. 10
• B. 20
• C. 30
• D. 5

Answer 1

The correct option is A 10

Given, P - Q - R , which means point Q is between P and R.

d(P, Q) = 10 units and d(P, R) = 20 units


From the figure,

d(P, Q) + d(Q, R) = d(P, R)

$\Rightarrow$ 10 + d(Q, R) = 20

$\Rightarrow$ d(Q, R) = 20 - 10

$\therefore$ d(Q, R) = 10 units