The average of five consecutive odd numbers is 21. What is the largest number out of these five numbers?

The average of five consecutive odd numbers is 21.

If the average of five consecutive odd numbers is 21, then 21 is the middle (third) number in this sequence. The numbers are equally spaced by 2 units (since they are consecutive odd numbers).

As consecutive odd number series average number is also middle number of the series.

So, series is;

17, 19, 21, 23, 25

Thus, The largest number out of these five numbers is 25.