Question

I need detailed explanation for this question pls help me....​

Answer 1

Answer:

(C) 4

Step-by-step explanation

See the attachment

Answer 2

in the table of 3:

3^1=3

3^2=9

3^3=27

3^4=81

again the same unit digits repeat in sequence of 4 no.'s

in table of 7:

7^1=7

7^2=49

7^3=343

7^4=2401

again the same repeats after the sequence of 4 no.'s

6^1=6

6^2=36

same goes on repeatedly

this is called cyclicity

now cyclicity of 3 is 6

for 7 is 4

for 6 it's 1

divide the powers with their cyclicity

for 3^65

65/4=1 is remainder

so 3^65 can be written as 3^1

for 6^59

6^n=1

for7^71

71/4=3 is remainder

equate the following

3^65*6^59*7^71

=3^1*6*7^3

=3*6*3

=4

therefore, 4 is the unit digit