Quant by Arun Sharma

Number System(Pg-46)--

Find the 28383rd term of the series: 123456789101112....

a) 3 b) 4 c) 9 d) 7

1-9 have 9 digits
10-99-89 digits
100-999-899 digits
and so on...just calculate in this way you will get your answer

i'm having problem in one question from Number system:
n is number such that 2n has 28 factors and 3n has 30 factors, 6n has
a) 35
b)32
c)28
d) None of these
plz tell me how to solve...

answer of this question would be
option (A)
"2n" has "28" factors
and 28 can be written as 7*4,14*2,28*1
similarly "3n" has 30 factors it can be written as,6*5,10*3,15*2,30*1
now the diff between case(1) and case(2) is that in (1) we added 2^1 in "N" and in (2) we added 3^1 so
a power of 2 will be reduced and a power of 3 will be increased hence on
7*4 and 6*5 satisfy this condition
i hope this will help

I dint get that above soln.. plz explain clearly. hey you all people hw is ur prep goin on? We need to discus more probs on nos. anyways..
here are some of my doubts plz share the soln of the following:

Q1)Remainder=? for 10^10+ 10^100+ 10^1000+.....+ 10^10000000000 divided by 7 is
a) 0 b) 1 c) 2 d) 5 e) 4

Q2) Remainder=? for 43^101 + 23^101 by 66:
a) 2 b) 10 c) 5 d) 0 e) 35


Q3) 10^n -(5+ sq root (17))^n is divisible by 2^(n+2) for wht whole no. value of n?
options : 2 ; 3 ; 7 ; 8; none of these

then the answer is e. None of these

I dint get that above soln.. plz explain clearly. hey you all people hw is ur prep goin on? We need to discus more probs on nos. anyways..
here are some of my doubts plz share the soln of the following:

Q1)Remainder=? for 10^10+ 10^100+ 10^1000+.....+ 10^10000000000 divided by 7 is
a) 0 b) 1 c) 2 d) 5 e) 4

Q2) Remainder=? for 43^101 + 23^101 by 66:
a) 2 b) 10 c) 5 d) 0 e) 35


Q3) 10^n -(5+ sq root (17))^n is divisible by 2^(n+2) for wht whole no. value of n?
options : 2 ; 3 ; 7 ; 8; none of these


Q1) Use Euler method, numerator will reduce to 10^5. 10^5mod7 = 5.
Q2) Euler method, Euler number of 66 = 20.. hence numerator will reduce to *43+*23 -> 43+23/66 -> remainder = 0.
Q3) Whatever values we put, there will always be a sq rt 17 element, hence none of these.

Hi puys , i want to crosscheck one of arun sharma's question

Q) A lateral side of an isosceles triangle is 15cm and the altitude is 8cm . What is the radius of the circumscribed circle?

i want to ask whether the circumcenter lie on the altitude of the triangle or not.

my answer is 225/16.
Thanx in advance

This is how i see it.. 58! - 38 ! can be written as 38!(58*57*56...39 - 1).. Now 58*57*56...39 is a multiple of 3.. Any multiple of 3 minus 1 is not a multiple of 3... Therefore the power of 3 will solely be determined by 38!.. It will be 12+4+1= 17...

Q1) Use Euler method, numerator will reduce to 10^5. 10^5mod7 = 5.
Q2) Euler method, Euler number of 66 = 20.. hence numerator will reduce to [43^(20*5)]*43+[23^(20*5)]*23 -> 43+23/66 -> remainder = 0.
Q3) Whatever values we put, there will always be a sq rt 17 element, hence none of these.

hw to solve [ 10^10+ 10^100+ 10^1000+.....+ 10^10000000000 ] / 7 , remainder ?

plz explain in detail?
hw to solve [ 10^10+ 10^100+ 10^1000+.....+ 10^10000000000 ] / 7 , remainder ?

plz explain in detail?


[10^10 + 10^100 .... 10 terms]/7

Euler number for 7 = 6.

[(10^6)*(10^4) + (10^{16*6})*(10^4) + ... 10 terms]/7

first term in each product gives a remainder 1 on being divided by 7.

10^4 + 10^ 4 + 10^4 .... 10 terms = 10 * (10^4) = 10^5

10^5/7 --> 3^5/7 = [(3*3)*(3*3)*3]/7 = 2*2*3/7

Remainder = 5.
Hi puys , i want to crosscheck one of arun sharma's question

Q) A lateral side of an isosceles triangle is 15cm and the altitude is 8cm . What is the radius of the circumscribed circle?

i want to ask whether the circumcenter lie on the altitude of the triangle or not.

my answer is 225/16.
Thanx in advance


It lies on altitude as perpendicular drawn from vertex to unequal side bisects it.
/7

Euler number for 7 = 6.

/7

first term in each product gives a remainder 1 on being divided by 7.

10^4 + 10^ 4 + 10^4 .... 10 terms = 10 * (10^4) = 10^5

10^5/7 --> 3^5/7 = /7 = 2*2*3/7

Remainder = 5.

========================================
thank you dude I was trying to make the power of 10^10 raise to the power and then GP..

Pg 166
Q 26: In a village consisting of p persons, x% can read and write. Of the males alone y% , and of the females alone z% can read and write. Find the number of males in the village in terms of p,x,y and z if z

Pg 166
Q 26: In a village consisting of p persons, x% can read and write. Of the males alone y% , and of the females alone z% can read and write. Find the number of males in the village in terms of p,x,y and z if z


Take the total population be 100 [=p] : 70 males, 30 females.

Let 20% [=y] of males are educated = 14.

Let 10% [=z] of females are educated = 3.

x = 17.

put the values in the options.

Answer: (d)
Toughluck2009 Says
It lies on altitude as perpendicular drawn from vertex to unequal side bisects it.

Brother, pls also tell what answer u are getting

can nybdy explain the following problem with proper soln,,,

N=202*20002*200000002*200...2(15zeros) * 2000.......2(31zeros). sum of digit in this multiplication will be :
112; 160; 144; can't be determined??

############common u people ...solve the problem yar.. Estaller whr are you... waiting 4 the past 3-4 days to get the damn soln..of above problem..

This is another question from lovely "Arun Sharma's book"
I am also uploading the figure. The question is
Q)A circle is inscribed in the quadilateral ABCD. Given that AB = 27cm, BC=38m, DC= 25cm and AD is perpendicular to DC. Find the maximum limit of radius and the area of the circle
a)10cm,226cm^2 b) 14cm,616cm^2 c)14cm,216cm^2 d)28cm,616cm^2
e) none of these

My approach was since OP=OS (radii) and PD=PS(tangents) and angle D= S=P=90 , hence OPDS is a square , i determined AD by foll. method
AD=AP+PD
= 27-TB+PD (since AP= AT as both are tangents and AT= 27-TB)
= 27-(38-SC)+PD
= 27-(38-SC)+(25-SC) (since PD=SD and SD= 25-SC)
AD = 14cm
and as from fig. AD= AP+PD , PD has to be smaller than 14cm under any condition and PD= OS radius of the circle , therefore the radius of the circle will definately be less than 14cm but Arun Sharma is saying answer as option(d) radius = 28cm which is not possible . At the back the book gives explanation as "WORK THROUGH THE OPTIONS"

PS: Estallar bhai aap kahaan ho ajkal:biggrin: , zara help karo

(Pg-44) Three numbers are such that the second is as much lesser than the third as the first is lesser than the second.If the product of the two smaller numbers is 85 and the product of two larger numbers is 115,find the middle number

x and y are two positive integers. Then what will be the sum of the coefficients of the expansion of the expression (x+y)^44?

a) 2^43
b) 2^43 + 1
c) 2^44
d) 2^44 - 1
:banghead:

x and y are two positive integers. Then what will be the sum of the coefficients of the expansion of the expression (x+y)^44?

a) 2^43
b) 2^43 + 1
c) 2^44
d) 2^44 - 1
:banghead:



Check for (x+y)^2 and (x+y)^3.

Sum of coefficients is always 2^n for (x+y)^n
piyush_1987 Says
(Pg-44) Three numbers are such that the second is as much lesser than the third as the first is lesser than the second.If the product of the two smaller numbers is 85 and the product of two larger numbers is 115,find the middle number


the three numbers are in AP.
let the nos. be (a-n), a, (a+n).
a^2-n = 85.
a^2+n = 115.
Solving, a^2 = 100, a = 10.

Require clarification on the below issue:-

In Arun Sharma's Number System Chapter,there is a Topic related to Finding the highest power (n) of a number which divides a Factorial number(xy00!) completely.
In this topic, i have a major problem in solving the different type of questions.

Ques1.Highest Power of 82 which divides 342!
Ans1. 7x3x2x2 . In this case which check only for no. of 7s.

But in Ques2. Highest Power of 175 which divides 344!
Ans2. 5x5x7 . But in this case we find no. of 7s as well as 5^2s.

Why so?

Also provide solutions to the below Questions with Explanations:-

Ques1> Highest Power of 12600 which divides 50!
Ques2>Highest Power of 720 which divides 77!
Ques3> Highest Power of 2520 which divides 50!

P.S. The main point of concern is how we determine which terms need to be counted for finding the answer?