Prasad moves towards North a distance of 10 km after which, he turns towards East and travels 20 km at which point, he turns South and continues for another 10 km. Finally, he moves 7 km West. How far is he from the starting point?
P, Q, R and S are playing a game of carrom. P, R and S, Q are partners. 'S' is to the right of 'R'. If 'R' is facing West, then 'Q' is facing which direction?