Question

in ap third term is obtained by adding 12 to first term and the last term of ap is 205 then find rhe number of terms in ap.

Answer 1

Answer:

[(205-x) ×12]+1

Step-by-step explanation:

Let tne number of terms in ap be n.

Here it is given that the difference (d) is12.

Also the last term is 205.

Let the first term be x.

According to the formula,

L=x+(n-1) d

Putting the values,

205=x+(n-1) 12.

n-1=(205-x) ×12

n=[(205-x) ×12]+1