QBM002

M151. What is the total number of different divisors including 1 and the number that can divide the number 3600? M152. A set X consists of 100 natural nos, each of which is a perfect cube. The maximum no of elements of X that one can always find such that each of them leaves the same remainder when divided by 17 is M153. Let x and y be positive whole numbers, and let p be any odd prime. It is well known that x3 + y3 is never equal to an odd prime. But given that n is a positive integer which contains an odd factor greater than one, prove that xn + yn = p has no solutions. M154. The largest number amongst the following that will perfectly divide 101100 - 1 is (1) 100 (2) 10,000 (3) 100100 (4) 100,000 M155. (x, y) is a pair of non-negative integers such that (x+ y - 5)^2 = 9xy. What are the possible values of (x,y) QM156. QM157. How many four digit numbers exist which can be formed by using the digits 2, 3, 5 and 7 once only such that they are divisible by 25? M158. A positive integer, n, is divided by d and the quotient and remainder are q and r respectively. In addition d, q, and r are consecutive positive integer terms in a geometric sequence, but not necessarily in that order. M159. Given that x and y are integer, how many different solutions does the equation |x| + 2|y| = 100 have? M160. A number consisting entirely of the digit one is called a repunit; for example, 11111. Find the smallest repunit that is divisible by 63. END

Q 151

total no.of factors = 45 + 2 = 47

 

Abi

HUMRAJ!!!!!!!

@Abhishek

Q.151

3600 =24 x 32 x 52

total factors = 5x3x3 = 45.

Q 157

32...4 digit numbers can be formed

Abi

Thanks

Hey..... yea..sorry... i thought 45 does not include 1 and the number 3600..jus referred a book n confirmed..

45 is the answer..

Thanks

Abi

Thanks

Hey..... yea..sorry... i thought 45 does not include 1 and the number 3600..jus referred a book n confirmed..

45 is the answer..

Thanks

Abi

M 160

Ans: 111111

clue... the number should be divisible by 7 and 3

Abi

Q157

Here unit place should be = 5 i.e 1 way

Ten place can be 2 or 7 i.e 2 way

Balance two number cane be arranged thus 1x2x2x1 =4 Ans

Q159

Here |x| + 2|y| = 100 or |y| = (100 -|x|)/2.

Thus Here |y)| .=0 thue the values for

x=0 y=-100 and +100 = 2sol

x=2 and x=-2 y=-46and+46 thus 4 ways

... x=100 or x=-100 then y = 0  2 ways

Solution = 2+4+4+...+2 where 2n-2 =100 or n =51 term is 100 thus 4+..4+(50times) = 4x50=200 Ans.

HUMRAJ!!!!!

M158. A positive integer, n, is divided by d and the quotient and remainder are q and r respectively. In addition d, q, and r are consecutive positive integer terms in a geometric sequence, but not necessarily in that order.

n = q.d + r

Then r< d and (d - r) is ethier 1 or 2.

i cant understand........., how it solve?????????

HUMRAJ!!!!

M155. (x, y) is a pair of non-negative integers such that (x+ y - 5)2  = 9xy.
What are the possible values of (x,y)?

Sol.

only two possible pairs of (x, y) are (0, 5) and (5, 0)

Some solution

M158. A positive integer, n, is divided by d and the quotient and remainder are q and r respectively. In addition d, q, and r are consecutive positive integer terms in a geometric sequence, but not necessarily in that order.
Ans. There is no solution like this.

M160. A number consisting entirely of the digit one is called a repunit; for example, 11111.
Find the smallest repunit that is divisible by 63.
The factors of 63 =3^2x7
Smallest unit divisibele by 9 is 1... n times. and four 7 it gives 1-2-3 ,-1,2,3,1,-2,-3 = 1-2-3=-4 not divisible by 7
The number divisible by 7 are 6 or 12 or 18 digit which is multiple of 9 also thus smallest repit is 111.. total 18 times.

159   Number of solutions

159

 

Number of solutions wud be infinite...Best way is to  make a graph for the equation...

M155

(1,1) is also there...

Q 152

answer seems to be 100 itself. if u take 17^3.. it will give u a reminder 0 when divided by 17. again the (17^3)^3 will agian leave 0 as reminder when div by 17.. so in that fasion there will be 100 no.s/.. Am i correct?

Q 158..

There can be a solution. thake n= 34, d=8, =then q= 4 and r=2...... 2 , 4, 8 are in GP !!!.... Am i correct?

cudn't understand the

cudn't understand the solution to 152.plz elaborate

Q 159

the answer will be 198 as two pairs (0,50) and (0 ,-50) will be common.

Q 155

i dont know how to solve this question.see there are many pairs (0,5) (5,0) (5,45) (45,5) (1,1) and even more i cany say.

(x+y-5)(x+y-5)=3x.3y

so
x+y-5=3x
x+y-5=3y and solve this

x+y-5=9x
x+y-5=y and solve this

x+y-5=x
x+y-5=9y and solve this


M . 152)   16


M . 152)   16

answer is..45 no need to add 2 as 1 and 3600 are already include

answer is..45 no need to add 2 as 1 and 3600 are already include

Ques 152 no dude...

correct answer is five only...
from 1^3 to 17^3 each willl give a different reminder fronm 18 onwards the repeation of reminder starts.

rem of 18^3 is equal ti 1^3 and so on..
finally we get 5 as answer check it..

M160:no dude check for it

1111..9times..
i think i'm correct..


here it goes..
111..ntimes./(9*7)
sum should be divisible by 9 then numerator willl be divisible by 9.
111...9times
now for 7 divide rest of numearator..122345679
it is divisible...

Q 160

d smallest such nmbr will be 18 1's...m i crrect???