Enzymatic reaction and Q10

The book below (refering to enzymatic reactions)  says:
 "...cooling to 200K reduces its speed by six orders of magnitude.An intermediate with a lifetime of 1ms at room temperature may thus be stable for a few hours at 200K."

https://books.google.gr/books?id=M_oox7T5zOsC&pg=PA41&lpg=PA41&dq=enzymatic+reactions+stop+and+subzero&source=bl&ots=Rv8CezI7bP&sig=_zTbRuqbRoGzD3v1uTibychDVXQ&hl=el&sa=X&ved=0ahUKEwiGhMPC7oTNAhUrDMAKHdslDLsQ6AEIPjAF#v=snippet&q=%22an%20intermediate%20with%20a%20lifetime%22&f=false

But I did my own calculations and if we assume a reaction has a Q10=2,
then at 200K(-73C) the reaction rate(speed)is about 0,2% of the reaction rate at
room temperature(20C). Which is 3 orders of magnitude reduced, not six.
Also the lifetime should be at the order of seconds and not hours as the book says.

So is the book correct and me wrong or vice versa?