Your question is Choose Mailing Option. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
A bill can be mailed using low-end mail or high-end mail. The costs are $0.40 and $1.00 per mail, respectively. Given different scenarios with mail list length and response probabilities (high: 0.7, low: 0.3), how would you decide which mailing option to use?