SSC JE Civil Engineering 30-Oct-2020 Shift 2 Paper

Representing the given information on NESW : The shortest distance between home and school is OA.
AB = AC + CB
AB = 30 + 60
AB = 90 m.
OB = 120 m.
Applying Pythagoras theorem in ΔAOB :
(Hypotenuse)2 = (Base)2 + (Perpendicular)2
(AO)2 = (BO)2 + (AB)2
(AO)2 = 1202 + 902
(AO)2 = 14400 + 8100
(AO)2 = 22500
AO = √22500
AO = 150 m.
So, the shortest distance between home and school is 150 m.
Hence, the correct answer is "150 m".