Ravi walks along a straight road as follows. Starting from the gate of his house, he walks 40m east to a shop and then another 25m east to a park bench. Ravi now selects the park bench as a new origin. From the bench he walks 50m west.
(a) Determine Ravi's position relative to the house gate after he reaches the park bench.
(b) Express the position obtained in (a) with respect to the park bench taken as origin.
(c) After walking 50m west from the bench, find Ravi's final position relative to the park bench and calculate his total displacement for the entire walk relative to the bench.