find 9th term from and of AP5,9,13______185
Answers
d=-4
n=9
an=a+(n-1)d
an=185+8*-4
an=153
Thus is the right ans
Question:- find 9th term from end of AP 5,9,13______185
Answer :- 153
Step by Step Solution:-
We have, Given series|
5 , 9 , 13 , .............185
First term of AP(a) = 5
Last term of AP (l) = 185
Common Difference (d) = 9 - 5 = 4
We know that,
nth term of AP from the end = l - (n-1)d
9th term of AP from the end = 185 - (9-1)*4
= 185 - 8*4
= 185 - 32
= 153
Alternating Method:- If we reverse the series like this,
185 ......,,,,,,,,,,13 , 9 , 5
Now, 9th term from the end of old AP will be euqal to 9th from starting of this AP.
Quick Solution:-
a = 185
d = 9 - 13 = -4
T₉ = a + (9-1)d
T₉ = 185 +(8)(-4)
T₉ = 153