Question

How many yarns of A.P. 4'9'14'.... Will make the make the sum 837?

Answer 1

given
sn = 837
n/2 *2a + (n-1)d = 837
n/2*2*4 +(n-1) 5 = 837
n/2 *4 +5n -5 = 837
2n + 5n -5=837
7n = 837-5
n= 832/7
n=118 (app)



i got this answer