Answer: Mixed fraction in simplest form is given by

Explanation:
Since we have given that,
A share of stock gained a total points = 1.64
Since it has a whole part i.e. 1 and decimal part i.e. 64 which is convert into a fraction as it is 0.64 , we will divide it by 100 to remove the decimal and make it a fraction.
In mixed fraction , we will write as

Hence, we get a required answer.