Question

Find the common difference and 15th term of the

a.p. 125, 120, 115, 110, g.

Answer 1

a1 = a = 125
a2 = 120
d = a2 - a1 = 120 - 125 = -5

a15 = a + (15-1)d = a + 14d = 125 + 14 × -5
= 125 - 70 = 55