# ISSUES

**Problems in Elementary Number Theory 1 [ 2008 ] No. 1**

**K12, H15, O53, I11, J11, A03, D02, O35, B06, O49**

**Problems in Elementary Number Theory 2 [ 2009 ] No. 1
**

**K11, I10, A14 & A71, N17, D05 & D06 & (M16), C2, (Q7), A13, A23 & A24, E16, A37 & A9 & O51
**

**Problems in Elementary Number Theory 2 [ 2009 ] No. 2
**

will be weblished around **December, 2009**.

on June 19, 2009 at 8:26 am |Problems in Elementary Number Theory 1 [ 2009 ] No. 2 « Project PEN[…] I […]

on June 20, 2009 at 1:40 pm |Mnajil P. SaikiaGreat.Keep it up!

on June 22, 2009 at 2:21 pm |Editors-in-Chief for 2010 « Project PEN[…] I […]

on June 22, 2009 at 2:31 pm |Project PEN: Editors-in-Chief for 2010 « ideahitme[…] PEN: Editors-in-Chief for 2010 By compactorange As you know, Problems in Elementary Number Theory 2 [ 2009 ] No. 1 is NOW […]

on June 23, 2009 at 1:18 pm |PEN Global « Project PEN[…] I […]

on November 17, 2009 at 3:50 pm |គណិតវិទ្យាថ្ងៃនេះHello ! My name is phalkun lim . I live in Cambodia !

I have a problem in Mathematics ! Please solving to me !

Find numbers x= H U N S E N and y = S T R O N G

if H U N S E N x 3 = S T R O N G

Thanks!

on November 29, 2009 at 5:15 pm |Andrew126356 E=5 G=8 H=1 N=6 O=0 R=9 S=3 T=7 U=2

126356

+126356

——-

379068

318928 E=2 G=4 H=3 N=8 O=7 R=6 S=9 T=5 U=1

318928

+318928

——-

956784

on December 3, 2009 at 11:23 pm |គណិតវិទ្យាថ្ងៃនេះThanks! Andrew.

on December 3, 2009 at 11:49 pm |ទ្រឹស្តីចំនួនលើ HUNSEN X 3 = STRONG « គណិតវិទ្យាថ្ងៃនេះ[…] Project PEN […]

on December 4, 2009 at 9:38 pm |គណិតវិទ្យាថ្ងៃនេះCompute the sum

S=1X9+2X99+3X999+4X9999+…….+n (999…..999)

on March 5, 2010 at 9:34 am |Kamal LohiaS = 1(10 – 1) + 2(100 – 1) + … + n(100…n zeroes – 1)

S = 1(10^1) + 2(10^2) + … + n(10^n) – (1 + 2 + … + n)

Now let S = P + Q

where P = 1(10^1) + 2(10^2) + … + n(10^n) and Q = (1 + 2 + … + n) = n(n + 1)/2

Now 10P = 1(10^2) + 2(10^3) + … + n(10^n+1)

=> 9P = -(10^1 + 10^2 + … + 10^n) + n(10^n+1)

=> P = n(10^n+1)/9 – 10(10^n – 1)/81

on March 8, 2010 at 1:39 pm |គណិតវិទ្យាថ្ងៃនេះThanks for your solution

on March 8, 2010 at 2:12 pm |គណិតវិទ្យាថ្ងៃនេះLet A , B , C are arithmetic sequence and N= ACB is perfect squares.

Find A , B , C

(0<A<9,0<B<9,0<C<9)

on August 2, 2010 at 12:49 pm |Kamal LohiaA = 5, B = 6, C = 7 and ACB = 576 = 24^2

on July 3, 2010 at 3:31 am |hungvuongthanks

on July 25, 2010 at 4:41 am |គណិតវិទ្យាថ្ងៃនេះHello ! today I have some problems !

I- find all functions f:IN to IR that :

f(0)=f(1)=f(2)=3 and f(n+3)=3f(n+2)-3f(n+1)+f(n)+2n+3

II-Let f(n) for n=1 , 2 , 3 , ….

f(1)=257/16 , f(2)=65/8 and f(n+2)=(5/2) f(n+1)-f(n) .

find n if f(n) minimum ?

III-Find of Sum :

S=1!1.2+2!2.3+3!3.4+4!.4.5+….+n!n(n+2)

IV-find all n on IN if n(n+1)(n+2) devised by 7 .

V- find a , b , c , d , e if abcde X 4 = edcba

on August 2, 2010 at 12:57 pm |Kamal LohiaV – 21978 * 4 = 87912.

IV – n = 0, -1, -2 mod7.

on October 8, 2010 at 5:16 am |គណិតវិទ្យាថ្ងៃនេះfind all a and b in IN and a different b such that aaaaab =0 (mod 7 )

on February 25, 2011 at 10:42 am |Quant Masterb – a = 0 mod7

As a and b are different integers, we can have (a, b) = (9, 2), or (8, 1).

on March 18, 2011 at 4:19 pm |គណិតវិទ្យាថ្ងៃនេះCompute the sum :

S=a+aa+aaa+aaaa+….+aaa….aaaa

on July 20, 2011 at 12:21 pm |គណិតវិទ្យាថ្ងៃនេះFind a such that : 21a78|87a12 ?

on October 28, 2014 at 2:57 am |Jonathan RamachandranBe Blessed for freely giving your work out!!

Thank You.

Sincerely,

(Anonymous Christian)