Great! Of those 8 customers, how many also have the status of "Shipped"?
select count ( * )  from  ( SELECT T1.customer_name FROM customers AS T1 JOIN orders AS T2 ON T1.customer_id  =  T2.customer_id WHERE T2.order_status  =  "On Road" INTERSECT SELECT T1.customer_name FROM customers AS T1 JOIN orders AS T2 ON T1.customer_id  =  T2.customer_id WHERE T2.order_status  =  "Shipped" ) 
count of customers with both 'On Road' and 'Shipped' status refers to using INTERSECT between two SELECT statements on orders with 'On Road' and 'Shipped' order_status;