Solution:

Coins of the Indian rupee were first minted in 1950. New coins have been produced annually since then and they make up a valuable aspect of the Indian currency system. All of these are produced by four mints located across India, in Kolkata, Mumbai, Hyderabad and Noida.

From 1964 onwards, coins of various denominations were being issued made of Aluminum-Magnesium alloy. The increasing cost of issuing Cupro-Nickel coins was the main reason behind this decision. This year also saw the issuing of the first series of memorial coins in India. The first memorial coins were dedicated to the first prime minister of India, Jawaharlal Nehru. Till then, the government had issued coins in memory of several other leading public figures too. Most important among them is the father of the Indian nation, Mahatma Gandhi.