The sequence is
740, 707.60,675.20,642.80,...
Here first term is 740, and common difference, d is
[tex] 707.60-740 = -32.40 [/tex]
Now we use the formula of nth term, which is
[tex] a_{n} = a+(n-1)d [/tex]
Substituting the values of a,n and d, we will get
[tex] =740+(n-1)(-32.40), 23 months [/tex]
Correct option is the second option .