Microsoft Company Numerical Ability permutation and combination

how many 7 digit numbers are there that they have no repeating digit & not include digit 3 & 9?

Read Solution (Total 16)

Microsoft Other Question

given 1000 bottles of juice, one of them contains poison and tastes
bitter. Spot the spoiled bottle in minimum sips?
There are N number of detectives , each one knows an information, how many calls should they make so all the detectives know all the N number of info. ?