question_answer

Find the 9th term from the end (towards the first term) of the A.P 5, 9, 13,......, 185.

Answer:

Given, A.P. is 5, 9, 13,......, 185

\[l~=185\] and \[d=5-9=9-13=-4\]

then,              \[{{l}_{9}}=l+(n-1)d\]

\[=185+(9-1)(-4)\]

\[=185+8(-4)\]

\[\therefore {{l}_{9}}=153\]