20 percent. For example, there are 10 bolts.  Since the number of bolts is 25 percent of the number of items, there must be 40 nuts. The total number of items = 10 bolts + 40 nuts = 50.  So, 10/50 = 1/5 = 20%.

Meals on wheels!

Bill is the suspect if you read upside down the numbers it says: “Bill is boss. He sells oil.”