Because 17 - 14 = 14 - 11 = 3, the ratio of the arithmetic series is 3;
Then, A4 = 8 - 3 = 5; A3 = 5 - 3 = 2; A2 = 2 - 3 = -1; A1 = -1 - 3 = -4.
But 68 = A1 + ( n- 1 ) x r;
68 = -4 + ( n - 1) x 3;
( n - 1 ) x 3 = 72;
n - 1 = 24;
n = 25;
Finally, Sn = ( A1 + An) x n / 2; then, S25 = ( - 4 + 68) x 25/2;
S25 = 64 x 25 / 2;
S25 = 32 x 25;
S25 = 800;
The value of sum is 800.
He can because you can add it mentally. You can just have 23 in your head and count by adding 10 "4" times.
Hope this helped☺☺
I believe it might be A or C. Not really sure
The probability that the spinner will land on a number greater than 4 or on a shaded section is five-sixt
<h3>What is probability?</h3>
Probability is the likelihood or chance that an event will occur. Mathematically;
Probability = Expected/Total
If the spinner is spinned, the total outcome is 1/6
Pr(greater than 4) = 2/6 = 1/3
Pr(shaded section) = 3/6 = 1/2
Pr(number greater than 4 or on a shaded section) = 1/3 + 1/2
Pr(number greater than 4 or on a shaded section) = 5/6
Hence the probability that the spinner will land on a number greater than 4 or on a shaded section is five-sixths
Learn more on probability here: brainly.com/question/25870256
