Answer:
Let butterfly was at point O.After some time
Position of Butterfly(OA) = 20 m
After flying through certain distance
Butterfly moved in backward direction(AB) = -16 m
There is negative sign before number 16.It means butterfly moved in backward direction.
So, final position of butterfly
=OA - AB
=+20 +(-16)
=20-16
=4 m, from Initial position.
