which are the youngest mountain ranges  in the world ?

The Himalayan range is one of the youngest mountain ranges on the planet and consists mostly of uplifted sedimentary and metamorphic rock. According to the modern theory of plate tectonics, its formation is a result of a continental collision or orogeny along the convergent boundary (Main Himalayan Thrust) between the Indo-Australian Plate and the Eurasian Plate. The Arakan Yoma highlands in Myanmar and the Andaman and Nicobar Islands in the Bay of Bengal were also formed as a result of this collision.
Himalayan ranges passes though countries like India, Nepal, Bhutan, Pakistan, and China.

The youngest mountains are the Himalayan range passing though India, Nepal, Bhutan, Pakistan, and China