Answer:
a) 1680
<em>The number of ways to listen to four CDs from a selection of 8 CDs = 1680</em>
Step-by-step explanation:
<u><em>Explanation:-</em></u>
Given data the number of CD' s n = 8
<em>We have to selected '4' CD' s from total '8' CD's</em>
<em>By using permutations </em>
<em>The number of ways to listen to four CDs from a selection of 8 CDs.</em>
<em> = </em>
<em> </em>
<em> we know that </em>
<em>The number of ways to listen to four CDs from a selection of 8 CDs = 1680</em>
Answer: x=75
Explanation:
x+10+x+20=180
combine like terms
2x+30=180
subtract 30 from each side
2x=150
divide each side by 2
x=75
Answer:
sorry getting points
Step-by-step explanation:
we know that given terms were i geometric progression.
which means common ratio is same between two consecutive terms .
here we have 8,40,200,1000.
we know that common ratio =second term/first term =40/8=5.
so each and every terms is multiplied by 5 to get next term for this series the term after 1000 is 5000 =1000*5.
in part b we have another series which is having common ratio of -2.
so we need to multiply with -2 to find next term.
80*(-2)=-160.
for part c the common ratio is -2 .
so we need to multiply with -2 *previous term =-2*16 =-32.
