What is the sum of the first 23 terms of the series 44+39+34+29+24

The series is A. P. with first term = 44 and common difference = 39-44=-5 = 34 - 39

Sum of A. P. is S = n/2 (2a + (n-1) d)

Where a is first term, d is common difference and n no. Of terms

Here a = 44, d = - 5 and n = 23

S = 23 / 2 (2*44 + (23-1) (-5))

S=23/2 (88-110)

S = 23 / 2 (-22)

S = 23*-11

S = - 253