Let's go through step by step, starting from inside the while loop.
Is i > 0? Yes. Continue.
ITERATION 1:
i now equals 10 (100 / 10)
j now equals 1 (1 + 10 % 5)
Is i > 0? Yes. Continue.
ITERATION 2:
i now equals 10 (10 / 1)
j now equals 0 (1 + 1 % 5)
Is i > 0? Yes. Continue.
ITERATION 3:
i = i / j; now generates a DivideByZeroException, thus we get a run-time error.