1.
A person starts from point A and walks 3 km towards the east to reach point B.
From there, he turns left and travels three times the distance to reach point C.
Again, he turns left and travels five times the distance between A and B to reach
the destination D. What is the shortest distance between the starting point and
the destination?
A
B
C
D
E
3 km
9 km
15 km
9 km
AB = 3 km
BC = 3 × 3 = 9 km
CD = 3 × 5 = 15 km
AE = BC = 9 km
DE = CD − AB = 15 − 3 = 12 km
AD = √(12² + 9²) = √225 = 15 km
BC = 3 × 3 = 9 km
CD = 3 × 5 = 15 km
AE = BC = 9 km
DE = CD − AB = 15 − 3 = 12 km
AD = √(12² + 9²) = √225 = 15 km