50 minutes / 40 customers = 1.25 minutes/ customer
With 20 more customers, you will have a total of 40 + 20 = 60 customers.
To calculate the new delivery time, we multiply the delivery time per customer by the total number of customers:
1.25 minutes/ customer x 60 customers = 75 minutes
Therefore, it will take approximately 75 minutes to deliver newspapers to 60 customers if it originally took 50 minutes to deliver to 40 customers.