Small typo: "[...] what your software needed to do [...]."

Answer to question "How did you come up with 190 days" mentions the usage of "Team Velocity", when in fact the estimate of 190 is in workable days, with an assumed velocity of 1.0. The velocity of 0.7 is applied later.

The source code of the exercise on this page is not the same as the source code of the solution on p. 376 to which it
refers:

After "private String qk = ..." there's missing "private MercuryMeals instance;" (as on p. 376).

The first implementation line of "public MercuryMeals getInstance()" should read "this.instance = new MercuryMeals();",
as on p. 376.

Within the submitOrder method there's a missing ending brace of the try-block so that the code wouldn't compile. There
must be a "}" right before the "catch" keyword.

Same on page 377.

The calculation is incorrect:
0.8 x (13 - 4) = 7
should be:

Issue:
Task estimates to fix remaining bugs are incorrect.
Description:
According to the spike testing,
10 days (in fact, 16 days) is "working day" (time).
But, task estimates should be "person-day" (work).
So, it should be 10 x 3 (in fact, 16 x 3)
Problem:
If we correct this error, the iteration will need to be extended,
because the iteration need to finish {12 + 4 + (10x3)} days of work
(in fact, 12 + 4 + (16x3))