Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

How many combination of random samples of 4 students can be selected?
4 from a set of 12. So

495 combinations of 4 students can be selected.
Answer:
108
Step-by-step explanation:
Since 18 x 2 = 36 you can just multiply 54 x 2. 54 x 2 =108
believe the correct answer from the choices listed above is option B. The constant term of the expression represent the <span>fixed rental for the book which has a value of 2. Hope this answers the question. Have a nice day.
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If he hits the target 95% of the time, then you could say that he has a probability of 0.95, or 95% of hitting the target. Let p = the probability of hitting the target or p = 0.95. So you are interested that he misses the target at least once - this could be thought of as not getting a perfect score. So to get a perfect score, it is 0.95 for each target -- 0.95^15 for 15 targets is 0.464. Thus to miss at least one target he needs to NOT have a perfect score -- 1 - 0.464 = 0.536, or 53.6% of happening. Enjoy
Answer is option 4. working out attached
hope it helps :)