Statement - I : An exact number has infinite number of significant digits.
Statement - II :A number, which is not a measured value has infinite number of significant digits 

When a whole number is known exactly, it can be treated as having an infinite number of significant figures even when the zeros are not written out. Hence statement I is correct.

A number, which is not a measured value has infinite number of significant digits is true. For example one feet has 12 inches. It is not measured value so it can be written as 1feet=12.00000....$\infty$