1999 AMC 8 Problem 9

Below is the professionally curated solution for Problem 9 of the 1999 AMC 8, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1999 AMC 8 solutions, or check the answer key.

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Concepts:inclusion-exclusionVenn Diagram

Difficulty rating: 1020

9.

Three flower beds overlap as shown. Bed A has 500500 plants, bed B has 450450 plants, and bed C has 350350 plants. Beds A and B share 5050 plants, while beds A and C share 100.100. The total number of plants is

850850

10001000

11501150

13001300

14501450

Solution:

Note there are 50+100=15050 + 100 = 150 plants that are in two beds and there are no plants in all three beds.

The total number of plants is then 500+450+350150=1150. 500 + 450 + 350 - 150 = 1150. We subtract to get rid of the plants that we counted twice.

Thus, C is the correct answer.

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