The period of a pendulum is given by

since Karachi is near sea level, g is larger than it is on Mt. Everest. That means the pendulum will have a larger period on Mt. Everest than it would in Karachi.
Mv + mv = 2mv providing each momentum is in the same direction.
1/2 mv^2 + 1/2 mv^2 = mv^2
Done I don't know answer of this question or this photo is the answer can you tell me