Gateway Parts

A computer lab has 7 IBM computers, 4 Compaq computers, and 4 Gateway computers. If seating is random, then th?

A computer lab has 7 IBM computers, 4 Compaq computers, and 4 Gateway computers. If seating is random, then the probability of a student sitting at a Compaq OR a Gateway computer is: A. 4/15 B. 7/15 C. 8/15 D. 11/15

Public Comments

1. D
2. if a student chooses a computer completely at random then he has 15 choices (7+4+4) If he wants Compaq/Gateway computers, then he has 8 choices (4+4) So, probability = no. of favourable cases/total no. of cases = 8/15
3. There a 7 + 4 + 4 = 15 possible outcomes of which 4+4 = 8 are successful. The probability of success is 8/15
4. C. 8/15 Consider this as a "Yes/No." IBM is no, 7 of 15 Compaq and Gate are yes, so they add, (4 + 4)/15
5. There are 7 + 4 + 4 = 15 total possibilities. Of these, the 4 Compaqs and 4 Gateways make 8 favorable outcomes. If the student selects one at random to use, then the probability is 8/15. However, if you did the real experiment back when IBM still sold PCs, then the answer would be closer to A, since one of the Compaqs and three of the Gateways would be broken, and the student wouldn't sit there. :^)