Question

which term is obtained, if 60 is added to the 3 rd term of the arithmetic sequence 4,7,10,...? ​

Answer 1

arithmetic sequence 4,7,10,...

a = 4. d = 3

3rd term = 4 + 2x3

= 10

now,

3rd term + 60 = 70

let nth term = 70

=> 4 + (n - 1)3 = 70

=> 3n - 3. = 66

=> 3n = 69

=> n = 23

thus, 23th term = 3rd term + 60