P, Q and R are three towns. The distance between P and Q is 60 km

P, Q and R are three towns. The distance between P and Q is 60 km, whereas the distance between P and R is 80 km. Q is in the West of P and R is in the South of P. What is the distance between Q and R?

  1. 140 km
  2. 130 km
  3. 110 km
  4. 100 km

Answer

You can use Pythagoras Theorem to find the distance between Q and R.

QR2 = PQ2 + PR2

QR2 = (60)2 + (80)2

QR2 = 3600 + 6400

QR = 100 km

The correct option is D.