Un appareil envoie une lumière rouge toutes les 13 minutes 45 secondes et cet appareil émet un <<bip sonore >> toutes les 15 minutes 30 secondes . A ma plus grande surprise, il vient de faire les deux en même temps ! 1) dans combien de temps cela va-t-il se reproduire ? détailler.
2) Donner la réponse sous forme heure, minutes, secondes. Détailler ​​

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?