還是概率,數(shù)學(xué)英文都好的進
a calculator manufacturer checks for defective products by testing 3 calculators out of every lot of 12.if a defective calculator is found,the lot is rejected.
a.suppose 2 calculators in a lot are defective.calculate the probability that the lot will be rejected
b.the quality-control department wants to have at least a 30% chance of rejecting lots that contain only one defective calculator.is calculators in a lot of 12 sufficient?if not why and how to promote.suppose answer with mathematical calculations
第一問我就用,1減去（2選0）乘（10選3）除與（12選3）
第2問.我不太明白究竟要怎么做.達(dá)人們給點提示,思路是什么樣的
第一問是沒什么問題了。
第二問。你的思路是什么樣的呢。給說說吧