Question

6, 11, 16..... is an arithmetic sequence. Which is the first three digit number in this sequence?

Answer 1

Answer:

101 is the first three digit number in the sequence.

Step-by-step explanation:

Here, in this sequence a=6; d=11-6=5.

From the question:'The first three digit number'

From this sentence we can infer that the three digit number we are going to find will be ≥100

Therefore,tn ≥100

=> a+(n-1)d ≥100

on substituting,

=> 6+(n-1)5 ≥100

=> 5n-5 ≥100-6

=> 5n ≥99 =>n=99/5

=>n=19.8.

Here the nth term can be taken as the 20th term i.e n=20th term.

Therefore, the number present in 20th term will be our answer.

so, t20= a+(n-1)d

           =6+(20-1)5

           =6+19(5)

           =6+95

           =101

Hope it helps you:)

All the best!!!