I want accurate answer with proper explanation show all your work please   Fatima operates a food stand by herself where she can serve an average of 18 customers per hour

I want accurate answer with proper explanation show all your work please

Fatima operates a food stand by herself where she can serve
an average of 18 customers per hour. An average of 11
customers arrive to purchase food each hour.
Fatima must prep food when she is not serving customers.
Approximately how many minutes out of each hour does
Fatima have available for prepping food?
O 8.5 minutes
O 35.3 minutes
O 13.1 minutes
O 24.7 minutes
O 40.8 minutes
O 23.3 minutes
The average time a customer spends waiting in line is
approximately
minutes.
O 0.96
O 6.43
O 5.24
O 1.57
O 8.11

What is the variance of the number of customers arriving at
Fatima's stand per hour?
O 25.0
O 1.47
O 18.0
O 11.0
O 4.12
O 289.0

( O STANDS FOR AN ANSWER OPTION)