Explanation:

The Indian government had demonetised banknotes on two prior occasions—once in 1946 and once in 1978—and in both cases, the goal was to combat tax evasion via "black money" held outside the formal economic system. In 1978, the Janta Party coalition government demonetised banknotes of ?1,000, ?5,000 and ?10,000, again in the hopes of curbing counterfeit money and black money.