19. Each can of Brand A paint will cover 200 square feet. A building has two walls to be painted. One is a rectangle with length 30 feet and width 16.5 feet, and the other is a triangle with height 12 feet and base 16 feet. What is the least number of cans of Brand A paint that are needed to paint the two walls in their entirety?
Answer: B
Three cans of Brand A paint are needed to cover the walls.
To determine the least number of cans of Brand A paint needed, we first calculate the total area of the two walls and then divide that by the coverage per can. The total area comes out to 600 square feet, which requires three cans of paint since each can covers 200 square feet.
A) 2
Choosing 2 cans would provide a total coverage of only 400 square feet, which is insufficient for the total area of 600 square feet that needs to be painted. Therefore, this option is incorrect.
B) 3
This option is correct as three cans provide a total coverage of 600 square feet (3 cans x 200 square feet per can), exactly matching the total area of the walls. Thus, three cans are necessary to complete the painting.
C) 4
While 4 cans would cover 800 square feet, which is more than enough for the 600 square feet needed, it is not the least number of cans required. Hence, this option is excessive and therefore incorrect.
D) 5
Like option C, 5 cans offer an unnecessary amount of coverage, reaching 1000 square feet. This option is also not correct as it exceeds the requirement, making it an inefficient choice.
Conclusion
The correct answer is option B, as it accurately reflects the necessary number of cans needed to cover the total area of 600 square feet without excess. Options A, C, and D either fall short of the requirement or provide unnecessary excess coverage, failing to meet the question's criteria for the least number of cans needed.