Wheat and Chessboard Problem

Have you ever heard of this wheat and chessboard problem? Let us look at a short interesting story to understand this problem.

Story:

Once upon a time there lived a king. In those days, poets will approach kingdom to meet the king and they would praise him with poems in front of all members to get rewards. Similarly, a poor poet was approaching his king to sing his poems and get rewards from him.

On hearing his poem, the king was happy. He was ready to give anything that the poet would ask for. He told the poet to ask whatever he want.

The poet asked rice grains for the next 64 days. The king was surprised on hearing this. He said that he was ready to offer him precious stones and jewelers. But the poet insisted with rice grains. He said that he would take one rice grain for today and two rice grains for tomorrow and four rice grains for the third day (i.e. twice the number of rice grains he took the previous day).

The king laughed at him and he promised to fulfill his wish. He said he was ready to offer rice grains for the next 64 days. The king promised the poet in front of whole kingdom. In those days, the promises were meant to be fulfilled by one who is promising. As the king was a man of principles, he should fulfill his promise at any cost.

The poet took one rice grain for the first day and two rice grains for the second day and it goes on.

On calculating this, we get 1,84,46,74,40,73,70,96,00,000 (“Eighteen quintillion, four hundred and forty-six quadrillion, seven hundred and forty four trillion, seventy three billion, seven hundred and nine million, five hundred and fifty one thousand, six hundred and sixteen”)rice grains on 64th day.

Let us assume that one rice grain weights 0.03 grams (approximately). For 1,84,46,74,40,73,70,96,00,000 rice grains, it would be 553,402,322,211(“Five hundred fifty-three billion four hundred two million three hundred twenty-two thousand two hundred eleven”) tons of rice grains (approximately). For size comparison, it would be equal to the size of mount Everest.

The global rice production per annum is around 515 million tons (as of the year 2022). The king sold all his wealth but he could not fulfill the poet’s wish. The king asked poet to forgive for his mistake.

The poet forgive him and said that one should think before promising something to someone. Few things might seem nothing at the beginning, but in the end it would be far away from our imagination.

Hope you might have enjoyed reading the Wheat and Chessboard problem with an interesting short story narrating the problem.

Thank you for reading.