Here,` a = 1, d = square , t_(n) =149`
`t_(n) = a+ ( n-1) d `
` :. 149 = square ` `:. 149 = 2n -square` `:. n = square `
Activity `:` Here, a= 1 , d = 2, `t_(n) = 149`
`t_(n) = a + ( n -1)d`
`:. 149 = 1+ ( n -1) xx 2`
`:. 149 = 1+ 2n -2`
`:. 149 = 2n -1`
`:. 2n = 149 +1 = 150`
`:. n = ( 150)/(2)` `:. n = 75`