by jen Thu Jun 02, 2011 2:04 pm
Hi Anindita,
On average, about 2 minutes.
However, many people find DI quite challenging, so it is advisable to be very efficient on your other problems to ideally have a little extra "time in the bank" for the 4 DI problems you are likely to see. (That's one of the reasons for all those Fast Math quizzes!)
Sincerely,
Jen