First off, let's find the 1st term's value, and the 30th term's value,

$\bf a1=3(1)+2\implies a1=5\qquad \qquad \quad a30=3(30)+2\implies a30=92\\\\
-------------------------------\\\\
~~~~~~~\textit{ Sum of an arithmetic sequence}\\\\
S_n=\cfrac{n(a1+an)}{2}~ 
\begin{cases}
n=n^{th}\ term\\
a1=\textit{first term's value}\\
----------\\
a1=5\\
a30=92\\
n=30
\end{cases} \implies S_{30}=\cfrac{30(5+92)}{2}
\\\\\\
S_{30}=15(97)$

6 0

3 years ago

Read 2 more answers

A bag contains 10 blue, 6 green, and 4 red marbles. You choose a marble with one hand and then a second marble with the other ha

Sergeu [11.5K]

Answer:

6/95.

Step-by-step explanation:

Prob(red marble on the first choice) = 4/(10+6+4)

= 4/20

= 1/5.

Prob(green marble on the second draw) = 6/19.

Prob( read then a green)

= 1/5 * 6/19

= 6/95.

6 0

4 years ago

Find the final cost to the employer.

Lena [83]

The correct answer is A) $75.85.

A discount of 20% means that the cost is 80% of the original. 80%=80/100=0.8

0.8(129) = 103.20

A discount of 30% means that the cost is 70% of the amount before discount. 70%=70/100=0.7
0.7(103.20) = 72.24

A sales tax of 5% means that it is 105% of the amount pre-tax. 105%=105/100=1.05
1.05(72.24) ≈ 75.85

8 0

3 years ago