How many positive terms are in an arithmetic progression: 17.2; 17; 16.8

3

Step-by-step explanation:

a = first term = 17.2

tn = last term = 16.8

d= common difference = -0.2

n = number of terms = ?

To find the number of positive terms, we'll use the formula;

tn = a + (n - 1) d

Substituting the figures,

=> 16.8 = 17.2 + (n -1) -0.2

=> 16.8 - 17.2 = (n - 1) - 0.2

=> -0.4 = (n - 1) - 0.2

=> -0.4/-0.2 = n - 1

=> n - 1 = 2

=> n = 3

Therefore, the number of positive terms in the sequence is 3

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