The 28th term of an AP is-5.Find its common difference if its first term is 31
Let's denote the common difference of the arithmetic progression as "d" and the first term as "a1".
We know that the formula for the nth term of an arithmetic progression is:
an = a1 + (n-1)d
We are given that a28 = -5, a1 = 31, and n = 28. Plugging these values into the formula, we get:
-5 = 31 + (28-1)d
Simplifying, we get:
-5 = 31 + 27d
Subtracting 31 from both sides, we get:
-36 = 27d
Dividing both sides by 27, we get:
d = -36/27
Simplifying, we get:
d = -4/3
Therefore, the common difference of the arithmetic progression is -4/3.