Demand for a good is said to be inelastic if the quantity demanded increases substantially when the price falls by a large amount. true or false?

This is a false statement.

Explanation:

Price has certain effect on the demand of a product.

An increase in price may lead to higher demand while an decrease in price may lead to lower demand.

The increase or decrease in demand following the fall or rise in price varying amount different products.

Product demand is said to be elastic when a change in price has relatively big effect in the demand while it is said to be inelastic when a change in price lead to little change in demand of a product.

As a result, the statement quote in the question is false. Demand for a good should be said to be elastic instead given the quantity demanded increases substantially when the price falls by a large amount.