16/21 decimal rounded to the nearest hundreth

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236

The amount of tears in the room (denoted by ttt) can be defined as a function of the number of people present in the room (denoted by ppp), the number of chopped onions in the room (denoted by ooo), and the deliciousness of the onions (denoted by ddd) using this formula: t =3\cdot \dfrac{p\cdot o^3}{d^2}t=3? d 2 p? o 3 ?