Probability

Question 1

Arithmetic explicit

Answer 1

An =a1+(n-1)d

Question 2

Arithmetic sum

Answer 2

Sn= (n/2)(a1+an)

Question 3

Geometric explicit

Answer 3

An=a1(r^n-1)

Question 4

Geometric sum (infinite)

Answer 4

Sn=a1/(1-r)

Question 5

Geometric sum finite

Answer 5

Sn=a1((1-r^n)/(1-r)

Question 6

Probability of a and b

Answer 6

P(a)*P(b)

Question 7

Probability a or b

Answer 7

Pa+Pb+-Pa*Pb