Answer:
option A
Step-by-step explanation:
The given Series:
10,14,18,22,26... is an Arithmetic Progression.
Concept:
The difference between consecutive numbers always remains the same.
For instance:
14 - 10 = 18 - 14 = 22 - 18 = 4
This difference is known as the common difference.
In an A.P., the nth (an) term of a series can be found out by:
[tex] \boxed{ \sf{a _{n} = a + (n - 1)d}}[/tex]
Here,
- an is the nth term
- a is the first term of the series = 10
- n is the number of terms
- d is the common difference = 4
[Don't get confused by (n- 1), it's simply the number of terms - 1. If the number of terms, somehow, is (n - 1) itself, your formula will be an = a + ((n - 1) -1)d]
Soltution:
The first term of the given Series is 10.
==> a1 = 10
Finding an:
the nth term will be:
an = 10 + (n - 1)4
==> 10 + 4n - 4
==> 6 + 4n
Strategy:
All the given options have an and a(n-1). So we have to deduce a relation between an and a(n- 1).
Finding a(n-1):
==> a(n-1) = 10 + ((n - 1) -1)4
= 10 + (n- 2)4
= 10 + 4n - 8
= 4n + 2
Subtracting a(n-1) from an:
==> an - a(n-1) = 6 + 4n - (4n + 2)
==> an - a(n-1) = 6 + 4n - 4n - 2
==> an - a(n-1) = 4
==> an = 4 + a(n-1)
Hence, option A is the answer.
