An animal shelter worker is preparing formula for orphaned puppies. There are 9 puppies and each needs 2 ounces of formula. How many ounces must be prepared?

• A. 20 oz
• B. 22 oz
• C. 16 oz
• D. 18 oz

Answer: (D)

When multiple animals each need the same amount of formula, you multiply the number of animals by the amount per animal to get the total you must prepare. Here, nine puppies each require two ounces, so the total formula is 9 × 2 = 18 ounces. That ensures there’s enough for all puppies.

Other totals don’t fit because they correspond to different counts of puppies. For example, 16 ounces would cover eight puppies at two ounces each; 20 ounces would cover ten puppies; 22 ounces would cover eleven puppies. So the correct total for nine puppies is 18 ounces.