KCET2011MathematicsBinomial Theorem
The digit in the unit's place of 7¹⁷¹+(177) ! is
Options
- A3
- B2
- C1
- D0
Correct answer
C. 1
Step-by-step solution
Given expression (7)¹⁷¹+(177) ! We know that the cycle of 7 is 4 , i.e., (7)³=1 and in case of more the 4 number in factorial notation gives always 0 at unit place. (7³ )⁵⁷+(177) !=1+0=1