Given A. P. is – 40, -15, 10, 35, ……….
First term (a) = -40
Common difference (d) = Second term – fast term
= -15 – (- 40)
= 40 – 15
= 25
We know that, nth term of an A.P. an = a + (n – 1)d
Then, 10th term of A. P. a10 = -40 + (10 – 1)25
= – 40 + 9.25
= – 40 + 225
= 185
∴ 10th term of the A. P. is 185.