19/20, 17/20, .24, .19.
Hope that helps.
Answer:
The number they would count is 
Step-by-step explanation:
One mole is equal to 6.02214076x10^23 particles. In order to know the number counted by every human on Earth we simply multiply the number of humans times the count a "good counter" can achieve, 4x10^9x7.44x10^9 (for USA, change to 4x10^12 if you use de British English definition). Thus:

...........The answer is C
Answer:
f(2)=1/3
Step-by-step explanation:
x=3
f(sqrt(3+1))=1/3
f(sqrt(4))=1/3
f(2)=1/3
I think it’s all real numbers