Find the c.d if the 28th term of an arithmetic progression is -5 and the first term is 31
the 28th term is 31 + 27d = -5
I don't understand the question
To find the common difference (c.d) of an arithmetic progression (AP), we can use the formula:
Tn = a + (n - 1) * d
Where:
Tn = nth term of the AP
a = first term of the AP
n = position of the term in the AP
d = common difference of the AP
Given:
T28 = -5
a = 31
Using the formula, we can substitute the given values and solve for d:
-5 = 31 + (28 - 1) * d
-5 = 31 + 27d
Subtract 31 from both sides:
-5 - 31 = 27d
-36 = 27d
Divide by 27 on both sides:
d = -36 / 27
d = -4/3
Therefore, the common difference (c.d) of the arithmetic progression is -4/3.