A pattern exists among the units digit of the posers of 8 as shown in the diagram.

What is the units digit of 8 to the power of 62

A) 2

B) 4

C) 6

D) 8

E) None of the above

A pattern exists among the units digit of the posers of 8 as shown in the diagramWhat is the units digit of 8 to the power of 62A 2 B 4 C 6 D 8 E None of the ab class=

Respuesta :

Answer:

B) 4

Step-by-step explanation:

We can solve this by observing some pattern.

The powers ending in 4 as unit digit are:

[tex] {8}^{2} , {8}^{6} , {8}^{10} , {8}^{14} , {8}^{20} ,...[/tex]

The exponents form the sequence:

2,6,10,14,20,...

We need to check if 62 belongs to this sequence.

This is an arithmetic sequence with a common difference of 4 and a first term of 2.

The explicit formula is

[tex]2 + 4(n - 1)[/tex]

We equate this to 62 and solve for n.

[tex]2 + 4(n - 1) = 62 \\ 4(n - 1) = 60 \\ n - 1 = 15 \\ n = 16[/tex]

Since n is a natural number, 62 belongs to the sequence.

Hence

[tex] {8}^{62} [/tex]

will have a unit digit of 4.