Question Number 175011 by MathsFan last updated on 16/Aug/22
$$\mathrm{A}\:\mathrm{large}\:\mathrm{lot}\:\mathrm{of}\:\mathrm{tires}\:\mathrm{contain}\:\mathrm{5\%}\:\mathrm{defectives}. \\ $$$$\mathrm{4}\:\mathrm{tires}\:\mathrm{are}\:\mathrm{to}\:\mathrm{be}\:\mathrm{chosen}\:\mathrm{for}\:\mathrm{a}\:\mathrm{car}.\:\mathrm{Find} \\ $$$$\mathrm{the}\:\mathrm{probability}\:\mathrm{that}\:\mathrm{you}\:\mathrm{find} \\ $$$$\:\left(\mathrm{a}\right)\:\mathrm{2}\:\mathrm{defective}\:\mathrm{tires}\:\mathrm{before}\:\mathrm{4}\:\mathrm{good}\:\mathrm{ones} \\ $$$$\:\left(\mathrm{b}\right)\:\mathrm{at}\:\mathrm{most}\:\mathrm{2}\:\mathrm{defective}\:\mathrm{tires}\:\mathrm{before}\:\mathrm{4}\:\mathrm{good}\:\mathrm{ones}. \\ $$
Commented by mr W last updated on 16/Aug/22
$${you}\:{choose}\:\mathrm{4}\:{tires}.\:{what}\:{do}\:{you}\:{mean} \\ $$$${with}\:``\mathrm{2}\:{defective}\:{tires}\:{before}\:\mathrm{4}\:{good} \\ $$$${ones}''?\: \\ $$
Commented by MathsFan last updated on 16/Aug/22
$${ok} \\ $$