Guys plzz help :)show that 21^n cannot end with the digit 0, 2, 4, 6 and 8 for a...

Questions

July 2022 2 30 Report

Guys plzz help :)

show that 21^n cannot end with the digit 0, 2, 4, 6 and 8 for any natural number n.

miya10 21ⁿ cannot end with the digit 0,2,4,6,8
prime factorization of 21 = ( 7×3)ⁿ
Since prime factorization of 21 does not contain 0,2,4,6,8 it cannot end with these digit for any natural n

rohitkumargupta HELLO DEAR,

WE CAN WRITE 21^n =(3×7)^n

AND WE KNOW THAT ANY POWER OF 3 WE

CAN'T GET EVEN NO. AS ITS END DIGIT ,SAME GOES FOR 7 .

SO,

( 21 )n CANNOT END WITH DIGIT 0 , 2 , 4 , 6 AND 8 FOR ANY NATURAL No. n .

WE CHECK IT AS BY PUTTING THE VALUES OF n

when n=2

21² =441.

, ( End digit is not as 0 , 2 , 4 , 6 and 8 )

At n = 3

( 21 )3 = 9261 ( End digit is not as 0 , 2 , 4 , 6 and 8 )

At n = 10

( 21 )10 = 16679880978201 ( End digit is not as 0 , 2 , 4 , 6 and 8 )

SO WE CAN SAY THAT

( 21 )n cannot end with digit 0 , 2 , 4 , 6 and 8 for any natural no. n . ( Ans )

I HOPE ITS HELP YOU DEAR,
THANKS

Questions

Answers & Comments

Add an Answer

a woman takes up a job of 8000 rupees per month with an annual increment of 100 ...

if the nth term of an AP is (3n + 2) then find the sum of n terms of an AP...

Hey Guys plzzz answer this ......find the area of the segment of a circle of rad...

Heyy... plzz help If A(1,2) B(4,3) and C(6,6) are the 3 vertices of a parallelog...

Plzz help me to solve q10...

Class 10th students plzz tell..which extra book is best for sst boards revision....

the centre of a circle is (2 p - 1, 2p - 2 )if a circle passes through the point...

if the coordinates of the mid-points of the sides of triangle are (2,1) (3,-5) a...

Plzzz solve ques 5 Plzzzzz Guys...

GUYS PLZZ HELP ME TO ANSWER THIS QUESTION.....show that 4^n cannot end with the ...

Recommend Questions

Helpful Links

Helpful Social