Question

The digit at the unit place of P would be: Given, P=(6+1) (62+1) (63+1) ......... (6100+1)

• A. 7
• B. 9
• C. 1
• D. 3

Answer 1

Answer: (C)

1

Answer 2

Unit digit of 6x=6, x is a natural no.
⇒ In P, the number of terms is 100 and each term has a unit digit ‘7’.
⇒ Unit digit of P = Unit digit of ($7^{25\times4}$)=1
So the correct option is (C): 1.