Answer:
An explicit representation for the nth term of the sequence:

It means, option (B) should be true.
Step-by-step explanation:
Given the geometric sequence

A geometric sequence has a constant ratio, denoted by 'r', and is defined by

Determining the common ratios of all the adjacent terms

As the ratio is the same, so
r = 4
Given that f₁ = -1/2
substituting r = 4, and f₁ = -1/2 in the nth term


Thus, an explicit representation for the nth term of the sequence:

It means, option (B) should be true.
Given:
must correctly answer 80% of the questions
correctly answered questions = 26
incorrectly answered questions = 4
unanswered questions = 15
Total questions = 26 + 4 + 15 = 45
45 * 80% = 36 required correctly answered questions.
36 - 26 = 10
Out of 15 remaining questions, 10 questions must be correctly answered for Heidi to advance to the next level.