Study the information given below carefully and answer the questions that follow :
Facing South Dinesh walked 50 metres before turning to his left to walk 30 metres. From this points, he turned towards North and walked for 30 metres more before reaching his friend's house To return to his house he turned left and walked straight 30 metres.
How far is Dinesh's house house from his starting point ?
1) 20 m
2) 10 m
3) 15 m
4) 25 m
5) 18 m

Explanation

1, 20 m