CBSE BOARD X, asked by aasthakansal8011, 1 year ago

find 9th term from and of AP5,9,13______185

Answers

Answered by arnav1909
2
a=185
d=-4
n=9
an=a+(n-1)d
an=185+8*-4
an=153
Thus is the right ans
Answered by Shubhendu8898
5

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

Similar questions