Answer:
Number of term = 48
Step-by-step explanation:
GIven:
Arithmetic progression
2,5,8..
Total sum of Arithmetic progression is 392
Find:
Number of term
Computation:
First term a = 2
Difference d = 5 - 2 = 3
Sn = [n/2][2a + (n-1)d]
392 = [n/2][2(2) + (n-1)3]
392 = [n/2][4 + 3n - 3]
784 = [n][1 + 3n]
784 = n + 3n²
3n² + n - 784
n = 48 , n = -49
Number of term = 48
