F.5 MATHS題

First term, a = 123

Common difference, d = 110 - 123 = -13

Let there are n terms

So, a + (n - 1)d = 0 (For the positive terms)

123 + (n - 1)(-13) = 0

-13n + 136 = 0

n = 10.46

n = 10

So, the smallest positive term is the 10th term

The smallest term

= 123 + (10 - 1)(-13)

= 6