Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store
seo-qna
SearchIcon
banner

The last digit of the number 7886is
a. 9b. 7c. 3d. 1

Answer
VerifiedVerified
530.4k+ views
like imagedislike image
Hint- last digit means we need to check the unit digit in nx.For finding the unit digit number we must know the concept of cyclicity of power to a number.



For finding the last digit of the number, we will have to check unit digit in nx
So, check the unit digit in 7886
71=7
So, the unit digit is 7.
72=49
So, the unit digit is 9.
73=343
So, the unit digit is 3.
74=2401
So, the unit digit is 1.
75=16807
So, the unit digit is 7.
76=117649
So, the unit digit is 9.
Now we can see that after 4 steps the unit digits are repeating.
Now in the given number the power of 7 is 886.
So divide 886 by 4
8864=22124...............(1)
Now we are generalizing the number of form and the corresponding unit digit can be written as
4n=14n+1=74n+2=94n+3=3

Now as we see from equation (1) that the power of 7 which is 886 is of form
886=221(4)+2i.e4n+2
Hence the unit digit would be 9.
So, the correct answer is option (a).

Note- In such types of questions if we asked to find out the last digit of some nxnumber, first we have to check the unit digit and find after how many steps it gets repeated, then divide the power of number with the number of steps after which the unit digit is repeating then generalize the number as above we will get the required last digit of the given number.

Latest Vedantu courses for you
Grade 10 | CBSE | SCHOOL | English
Vedantu 10 CBSE Pro Course - (2025-26)
calendar iconAcademic year 2025-26
language iconENGLISH
book iconUnlimited access till final school exam
tick
School Full course for CBSE students
PhysicsPhysics
Social scienceSocial science
ChemistryChemistry
MathsMaths
BiologyBiology
EnglishEnglish
₹38,500 (9% Off)
₹35,000 per year
Select and buy
WhatsApp Banner