Answer:
d. converges, -25
Step-by-step explanation:
An infinite geometric series converges if the absolute value of the common ratio is less than 1.
Here, the common ratio is 4/5:
| 4/5 | = 4/5 < 1
So the series converges. The sum of an infinite geometric series is:
S = a₁ / (1 − r)
where a₁ is the first term and r is the common ratio.
Here, a₁ = -5 and r = 4/5:
S = -5 / (1 − 4/5)
S = -25
Answer: She has a $-7.50 balance
Step-by-step explanation: A = 3*12.5
A= 37.5
37.5-30= -7.5
Since we already know that there is a 25% chance to guess the correct answer to a multiple choice question, all we have to do is multiply .25 and 68 to get the expected amount of answers a student can possibly guess. We multiply .25 since it is the decimal form of 25% and 68 is our total questions.
.25 x 68 = 17
Therefore, a student can expect to guess 17 answers correct on a test with 68 multiple choice questions.