Answer:
24
Step-by-step explanation:
Since at the retailer you find a choice of 4 CD players, 2 amplifiers and 3 sets of speakers. We have 4 different ways of selecting the CD players, we also have 2 different ways of selecting the amplifiers and 3 different ways of selecting the 3 sets of speakers.
So, the total number of different HiFi systems are available to purchase from this retailer is 4 × 3 × 2 = 24 .
So we have 24 different HiFi systems are available to purchase from this retailer
Answer: 5 cos x
<u>Step-by-step explanation:</u>
y = sin x is y = cos x shifted to the right π/2 units.
y = 5 sin (x + π/2) is a shift to the left π/2 units (which results in cos x) and . an amplitude of 5.
--> y = 5 cos x
Answer:

Step-by-step explanation:
The sum of an infinite geometric series is expressed according to the formula;
where;
a is the first term of the series
r is the common ratio
If the sum of an infinite geometric series is three times the first term, this is expressed as 
Substitute
into the formula above to get the common ratio r;


open the parenthesis

subtract 3 from both sides

<em>Hence the common ratio of this series is </em>
<em></em>
Answer:
5208
Step-by-step explanation:
Answer: 8/33
Step-by-step explanation:
So the probability of picking a purple marble is 8/12, after that there are 11 marbles left in the box
Now the probability of picking a green marble without placing the first marble back is 4/11
So the probability of doing both is 8/12 x 4/11 = 8/33