Question

You have two jars, one jar which has 10 rings and the other has none. They are placed one above the other. You want to remove the last ring in the jar. And the second jar is weak and cannot be used to store rings for a long time.

(a) Empty the first jar by removing it one by one from the first jar and placing it into the second jar

(b) Empty the first jar by removing it one by one from the first jar and placing it into the second jar and empty the second jar by placing all the rings into the first jar one by one

(c) There exists no possible way to do this

(d) Break the jar and remove the last one

Answer 1

Correct option: (b) Empty the first jar by removing it one by one from the first jar and placing it into the second jar and empty the second jar by placing all the rings into the first jar one by one

This is similar to performing dequeue operation using push and pop only. Elements in the first jar are taken out and placed in the second jar. After removing the last element from the first jar, remove all the elements in the second jar and place them in the first jar.