Ishaan is standing at a bus stop facing the East. From there he turns right and starts walking for 30 m. Then he turns left and walks 10 m. He again turns left and walk 15 m. What is the shortest distance (approximate) between Ishaan and the starting point?

Ishan was initially facing east, so when he turned right, he faced south. 
Then he walked 30 m south. 
The then turned left, facing east, walked 10 m east. 
He then finally turned left again, facing north and walked 15m 

In essence, he walked 30 m south and 15 m not, making him move 15 m southwards. 
And he moved 10 m eastwards. 

Givng his net distance from his starting position to be $$\sqrt{\ 225-100}=\sqrt{\ 125}$$, which is slightly more than 11m