Question

The first term of an arithmetic sequence is -3 and the fifteenth term is 53 what is the common difference of the sequence

Answer 1

The 1st term = -3

15th term = 53

15th term = a + d(n-1)

53 = -3 + d(15- 1) [Here n = 15)

53 + 3 = d(14)

14d = 56

d = 4

The common difference is 4.