My recruiter called me about an interview next week. She didn't call me back the first time. The second time, she said she could arrange an interview for next week. I was so afraid of losing the opportunity that I agreed to take it, even though I did not have enough time to prepare. I think Google's interviews require intensive preparation.

Write a probability formula to tell how many bits will be changed when 1 is added to a 32-bit binary number.