1. what is the expected times of tossing the coins to get three heads in a row? (smart way is to use Markov process ) 2. sinx + x - 1 = 0, does the solution exist ? if yes, why it has solution and what is it. (I said the solution is close to be pi/2 by observing) 3. sth about ordinary least square, collinearity 4. one simple ODE question, what boundary conditions required to solve Y'' = 0 5. what algorithm used to find the first element greater than target in a sorted array ? The answer is binary search, you don't need to provide code. 6. There is another coding problem which I forgot.
