Question

Which term of the progression 20 19 18 17 is the first negative term?

Answer 1

Answer:

22th term

Step-by-step explanation:

The terms are in an arithmetic progression as they have a common difference i.e. d = 19 - 20 = - 1

a = 20, d = -1

By assumption, we can say that the first negative term of the sequence will be - 1.

Let $n {}^{th}$ of the sequence be - 1.

-1 = 20 + (n - 1) (-1)

-21 = - n + 1

n = 21 + 1

n = 22

Required answer = 22th term

Answer 2

Answer:

The progression will be as follows:

19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2.....

Clearly -1 is the first negative term