Which of the following formula gives the correct determination of the minimum number of test runs in a floating car method?

Which of the following formula gives the correct determination of the

1.	Which of the following formula gives the correct determination of the minimum number of test runs in a floating car method?
A.	N=((tα χ σ)/d*2)
B.	N=((tα χ σ)/d*3)
C.	N=((tα / σ)/d*2)
D.	N=((tα + σ)/d*2)
Answer» B. N=((tα χ σ)/d*3)