Answer:
Ordering of objects from heaviest to lightest are ⇒ <u> school bus weight 9 tons, elephant 5,500 kilograms, horse 1,100 pounds and grand piano 15,840 ounces.</u>
Step-by-step explanation:
Given:
School bus weight = 9 tons.
Horse = 1,100 pounds.
Elephant = 5,500 kilograms.
Grand piano = 15,840 ounces.
Now, order these objects from heaviest to lightest.
So, we need to take a common unit to order the items:
Thus, we take pounds as a common unit.
16 ounces = 1 pound.
1 kilogram = 2.2 pounds.
1 ton = 2,000 pounds.
Then, we calculate the weight of all items in pounds:
School bus 9 tons 
Horse 1100 pounds 
Elephant 5500 kilograms 
Grand piano 15840 ounces 
According to question:
Ordering from heaviest to lightest:
<em>School bus = 18000 pounds, elephant = 12100 pounds, horse = 1100 pounds and grand piano = 990 pounds.</em>
Therefore, ordering of objects from heaviest to lightest are ⇒ school bus weight 9 tons, elephant 5,500 kilograms, horse 1,100 pounds and grand piano 15,840 ounces.