Question

The owner of the Good Deals Store opens a new store across town. For the new store, the owner estimates that, during business hours, an average of $90$ shoppers per hour enter the store and each of them stays an average of $12$ minutes. The average number of shoppers in the new store at any time is what percent less than the average number of shoppers in the original store at any time?

• A. $60$
• B. $70$
• C. $80$
• D. $50$

Answer 1

The correct option is A $60$

The estimated average number of shoppers in the original store at any time is $45$. In the new store, the manager estimates that an average of $90$ shoppers per hour enter the store, which is equivalent to $1.5$ shoppers per minute.

The manager also estimates that each shopper stays in the store for an average of $12$ minutes. Thus, by Little’s law, there are, on average, $N=rt=\left(1.5\right)\left(12\right)=18$ shoppers in the new store at any time.

This is $\frac{45-18}{45}\times 100=60$ percent less than the average number of shoppers in the original store at any time.