Question

find the 11th term of an appointment 10,7,4.............

Answer 1

$an = a + (n - 1)\times d$
$a = 10$
$d= 7 - 10 = - 3$
$n = 11$
$an = 10 + 10 \times - 3 \\ = 10 + - 30 \\ = - 20$

therefore -20is the eleventh term of the AP!!

Answer 2

Firstly, That's no Appointment ..... That's an A.P.

Secondly, $T_1$ = 10 and common difference = (-3)

.'. $T_{11}$ = 10 + ( 11-1 )(-3) = 10 - 30 = -20