Question

The book store sells scientific and finance calculators with or without the calculator manual. The following are the combinations of the type of calculator and how many come with their manual. The event A is Texas Instrument calculator (45 calculators), the event B is that the calculator comes with a manual (90 calculators) and the Texas Instruments with manuals are 35 calculators. There is a total of 100 calculators in the book store. Compute the probability of AUB

Answer 1

Given:

The event A is Texas Instrument calculator = 45

The event B is that the calculator comes with a manual = 95

Texas Instruments with manuals (A and B) = 35

Total number of calculator = 100

Probability = Number of favourable outcomes/Total number of outcomes

So P(A) = 45/100,

P(B) = 95/100 and

P(A⋂B) = 35/100

The probability of AUB :

P( AUB) = P(A) + P(B) - P(A⋂B)

= 45/100 + 95/100 - 35/100

= (45+95-35)/100

= 105/100

= 21/20

Therefore P(AUB) = 1.05 = 21/20