Question

Find the 25^th term of the AP 5 , 4`1/2 , 4,3 1/2 ,3`.................

Answer 1

The given AP is 5 , 4`1/2 , 4,3 1/2 ,3`.................

First term = 5

Common difference` = 4 1/2 -5 ⇒ 9/2 -5 ⇒(9-10)/2 = -1/2`

∴  a= 5 and d= - `1/2`

Now , `T_25 = a + (25-1) d = a +24 d`

=`5 + 24 xx(-1/2) = 5 -12 =-7`

∴ 25^th term = -7