Ask Question
24 September, 23:16

Which answer describes this type of series - 20-18-15-11 - ...

A). Arithmetic

B). Geometric

C). Neither

D). Both

+3
Answers (2)
  1. 24 September, 23:19
    0
    Arithmetic sequences have a common difference, while Geometric sequences have a common ratio.

    In the sequence - 20, - 18, - 15, - 11 ..., there is not a common difference. This is because there is a + 2 increase between - 20 and - 18 but a + 3 difference between - 18 and - 15, then + 4 increase between - 15 and - 11.

    This means it is not Arithmetic, which means it can't be both either.

    This leaves us with B and C, so we have to see if there is a common ratio.

    To find common ratio, divide any 2 terms in the sequence.

    Let's choose - 18 and - 15.

    -18 / - 15 = 1.2

    Now let's see if this works for each term.

    To do this, multiply each term by 1.2 to see if it results in the next term.

    -20 • 1.2 = - 24 This doesn't work, so there is no common ratio.

    This means the sequence is neither Arithmetic nor Geometric.

    So the answer is C. Neither.
  2. 24 September, 23:25
    0
    The answer is C) Neither because their is no consistency in adding, subtracting, multiplying, or dividing
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “Which answer describes this type of series - 20-18-15-11 - ... A). Arithmetic B). Geometric C). Neither D). Both ...” in 📗 Mathematics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers