Answer:
Not effective: 31.5%
Effective: 68.5%
Step-by-step explanation:
200
First we need to figure out how many tests they did :)
20 x 10 = 200
Now lets divide to see the percentage of how effective and not effective it is :)
Not effective: 31.5%
63/200 = 0.315 x 100 = 31.5
Effective: 68.5%
137/200 = 0.685 x 100 = 68.5
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