Number System - Questions & Discussions

@[386572:pathetic]: Total no of codes :9X9=81


numbers which can be read upside down- 1,6,8,9

so two numbers can be selected from 4 in 4c2 ways=6 ways and can be arranged in 2 ways

so no of numbers which create confusion=12

so numbers which don't create confusion= 81-12=69 (Not in option)

Please correct me if i'm wrong

@priya.patil said:

@sandip.yadav here goes my proof

€Ž99(c - a) = 66k99(c - a) = 198, 396, 594, 792c - a = 2, 4, 6, 8for 2, 30 such numbersfor 4, 20 such numbersfor 6, 10 such numbers for 8, 0 such numbers so, 60 such numbers

so u plz check ur ans again ..

the algebric expression of the number is 99(x-z). for this number to be divisible by 66, (x-z) has to be even. i.e only an even multiple of 99 will be divisible by 66. so (x-z) can be 2/4/6/8. It's given to us that 'z' is even.
1. (X-Z) TO BE 2 - Z can be 2, 4, 6 and x will be 4, 6, 8 respectively. Z cannot be 8 coz as x and z are digital numbers, if z becomes 8 then x has to be 10 which is not possible. HENCE THREE SUCH NUMBERS, NAMELY (4,2) (6,4) (8,6)
2. (X-Z) TO BE 4 - Z can be 2 and 4 and x will this be 6 and 4 respectively. Z cannot be 6 and 8 for the reason stated in point 1. hence two numbers namely (2,6) (4,8).
3. (X-Z) TO BE 6 - Z can only be 2 and x will be 8. more than that is not possible. hence just one number namely (2,8).

thus we get in total 6 such numbers. now for these 6 numbers, x can take any value ranging from 0-9 because as we saw eventually 10y and 10y gets cancelled and they do not contribute anything. hence total such numbers satisfying the above given condition are 6*10= 60 numbers. hope this helped you Priya.. :)

Thanks Quantohelp for highlighting that.. I missed out on that!

@[547670:koyal1990] thanx yaar i got d ans..

@[584816:Lord.Joker]:

Hey actually it is not 12 because as per the solution we wont be considering 69 and 96 so answer is 81-10 = 71

Thanks for solving

please show the procedure!

Let Z = {1, 11, 111, 1111, ..., 11111 up to 55 times} and T be a subset of Z such that the sum of no two elements of T is divisible by 3. The maximum possible number of elements in T is:
a. 18 b. 19 c. 20 d. 37

I'm getting 37 as answer but the answer given is 20, please help!
@akansh_1 said: Let Z = {1, 11, 111, 1111, ..., 11111 up to 55 times} and T be a subset of Z such that the sum of no two elements of T is divisible by 3. The maximum possible number of elements in T is:a. 18 b. 19 c. 20 d. 37I'm getting 37 as answer but the answer given is 20, please help!
The elements are of 3 type:
3k -> 18 in total
3k + 1 -> 19 in total
3k + 2 -> 18 in total

For max possible no. of elements, we take all of type 3k+1, and one of type 3k.
So total = 19 + 1 = 20
@Angadbir said:
The elements are of 3 type:
3k -> 18 in total
3k + 1 -> 19 in total
3k + 2 -> 18 in total
For max possible no. of elements, we take all of type 3k+1, and one of type 3k.
So total = 19 + 1 = 20
Thanks a lot. I was including elements of both types- 3k and 3k+1, so was getting 37!
can anybody please help..??
can we apply to more than one management programs of a particular IIM while filling the form?
what if we apply to all the programs available in CAT form..

@[521497:aadit4you] You can apply to all programs given in the CAT form. for some programs, there are different qualification criteria like Work Ex and Sector of work ex- just check online in the respective iim's website whether you are eligible for the course if you have any doubts.

18^2000+12^2000-5^2000-1 is divisible by

a)323
b)221
c)299.
pls show detailed sol.
10000! = (100!)K P, where P and K are integers. What can be the maximum value of K?

a)104
b)103
c)102
d)105
pls show detailed sol.
@viveknitw said: please show the procedure!
for odd numbers, tn= 2^(n-1) + 1; so s(n=50) = summation[2^(n-1)] =50 =a;
it is a gp so its sum is: 1 (4^50 - 1)/4-1 + 50
similarly the sum for even n is 2 (4^50 -1)/4-1 - 50;
.
adding both of them wee get sum = 4^50 -1;
and to obtain its remainder, we will obtain remainder of 4^50, and will subtract 1 from that remainder;
so remainder of 2^100/127 is 16 and subtracting 1 we get 15.. but it is not in options..

The series of no.s (1, 1/2, 1/3, 1/4......1/1972) is taken. Now two no.s are taken from this series(the first two) say x, y. Then the operation x+y+x.y is performed to get a consolidated no. The process is repeated. What will be the value of the set after all no.s are consolidated into one number.

@surya the bacon said:The series of no.s (1, 1/2, 1/3, 1/4......1/1972) is taken. Now two no.s are taken from this series(the first two) say x, y. Then the operation x+y+x.y is performed to get a consolidated no. The process is repeated. What will be the value of the set after all no.s are consolidated into one number.
will be 1972. Try with first few nos.
@surya the bacon said: The series of no.s (1, 1/2, 1/3, 1/4......1/1972) is taken. Now two no.s are taken from this series(the first two) say x, y. Then the operation x+y+x.y is performed to get a consolidated no. The process is repeated. What will be the value of the set after all no.s are consolidated into one number.
1972

@[474787:deedeedudu] how to approach

please show the procedure!


@viveknitw said: please show the procedure!
for odd numbers, tn= 2^(n-1) + 1; so s(n=50) = summation[2^(n-1)] =50 =a;
it is a gp so its sum is: 1 (4^50 - 1)/4-1 + 50
similarly the sum for even n is 2 (4^50 -1)/4-1 - 50;
.
adding both of them wee get sum = 4^50 -1;
and to obtain its remainder, we will obtain remainder of 4^50, and will subtract 1 from that remainder;
so remainder of 2^100/127 is 16 and subtracting 1 we get 15.. but it is not in options..


could not understand @ @[599204:sandip.yadav]
plz xplain summation[2^(n-1)] =50 =a;???????????????

acc to me ans is 0