Question

In an arithmetic sequence 5,17,29,41... Find the position of 245

Answer 1

Answer:

given sequence is

5,17,29,41......

here,

first term( a ) = 5

common difference , d = 17-5 = 12

Last term, l = 245

let it's position be at nth place.

formula : l = a + ( n -1)d

$.$

=> 245 = 5 + ( n -1)12

=> 240-5 = (n -1) 12

=> 240 = (n -1)12

=> n-1 = 240/12

=> n-1 = 20

=> n = 20 +1

=> n = 21

so,

245 is the 21st term of this arithmetic progression..