Question

What is the 30th term of pattern with this rule. starting with 5 and keep adding 10

Answer 1

Explanation:

well, then you understand the pattern. and it is really simple.

a1 = 5

a2 = a1 + 10 = 5 + 10 = 15

a3 = a2 + 10 = a1 + 10 + 10 = 5 + 20 = 25

a4 = a3 + 10 = a2 + 10 + 10 = a1 + 10 + 10 + 10 = 5 + 30 = 35

...

do you see how that works ?

an = an-1 + 10 = a1 + (n-1)×10 = 5 + (n-1)×10

it works in general the same way for any constantly added numbers d :

an = a1 + (n-1)×d

so, for the requested a30 :

a30 = a29 + 10 = a1 + (30-1)×10 = 5 + 29×10 = 295

Answer 2

The pattern you described is an arithmetic sequence where each term is obtained by adding 10 to the previous term. The general formula for the nth term of an arithmetic sequence is given by:


So, the 30th term in the given pattern is 295.