The sum of the first 15 terms of an arithmetic progression is 255. What is the common difference if the first term is 3?
A. 3
B. 4
C. 2
D. 6
Answer:C
The sum of the first 15 terms of an arithmetic progression is 255. What is the common difference if the first term is 3?
A. 3 B. 4 C. 2 D. 6