official quant thread for cat08

[deep_agrawal]

Originally Posted by dashing

For "25^102/17"

102 is divisible by 17 so the remainder is zero

I believe you are incorrect.

Use Euler's to solve this problem:

So, 25^102/17 = 8^102/17.

Now, 8 and 17 are co-primes. Hence, 8^16/17 = 1.

Hence, 8^96/17 = 1.

Now we have 102-96 i.e. 8^6/17 remaining.

Solving this gives 4 as the answer.

A link to solve remainder problems using Euler's:

CAT 2007, CAT 2008, IIM, GMAT, MBA preparation, XAT, problems, math, quant, verbal, data interpretation, reading comprehension, sentence correction, critical reasoning, number system, geometry,

[prashant225]

Originally Posted by deep_agrawal

I believe you are incorrect.

Use Euler's to solve this problem:

So, 25^102/17 = 8^102/17.

Now, 8 and 17 are co-primes. Hence, 8^16/17 = 1.

Hence, 8^96/17 = 1.

Now we have 102-96 i.e. 8^6/17 remaining.

Solving this gives 4 as the answer.

A link to solve remainder problems using Euler's:

CAT 2007, CAT 2008, IIM, GMAT, MBA preparation, XAT, problems, math, quant, verbal, data interpretation, reading comprehension, sentence correction, critical reasoning, number system, geometry,

Great .Ya this is wat i was looking for.

Yaar deep wanted to know whether this total gadha has similar exposure like the one for remainder theory for other concepts.
Newayz thanx.
Cheers
prashant

[dashing]

Originally Posted by yudhajeet

"Dravid and Sachin each had a certain number of playing marbles. Dravid lost a game to Sachin and had to give Sachin half of his marbles. In the second game, Sachin lost and had to give three-fourths of his marbles to Dravid, who now had thirty marbles. Finally, the two played a third game. Sachin won and acquired some of Dravid?s marbles.At this point, each boy had exactly the number of marbles he had started with, and Dravid had twice as many marbles as Sachin. How many marbles did Sachin has in the beginning?"

Give 24 hrs before posting your answrs to this q..

the link in this quest is "each boy had exactly the number of marbles he had started with, and Dravid had twice as many marbles as Sachin"

suppose Sachin has s at the beginning, so dravid has 2s

So after 1st game ,
Sachin = 2s
Dravid = s

After Second game
Sachin = s/2
Dravid = s + 3s/2 = 5s/2

As given after second game Dravid has 30 marbles
so 5s/2 = 30
=> s = 12

Let the share thats exchanged after third game be x

So after third game
Sachin = s/2 + 5sx/2
Dravid = 30(1-x)

So sachin after third game has 12/2 + 60x/2 i.e. 6+30x
Since thats equal to his original share i.e. s i.e. 12

6+30x = 12
=> x = 1/5

the question asked is "How many marbles did Sachin has in the beginning?"
Answer is 12

Hope this is clear

[deep_agrawal]

Originally Posted by prashant225

Great .Ya this is wat i was looking for.

Yaar deep wanted to know whether this total gadha has similar exposure like the one for remainder theory for other concepts.
Newayz thanx.
Cheers
prashant

TotalGadha has quite some good articles related to quant. Although, i feel the article i have given you the link for is the best on TG. Remainder problem concepts have been explained very lucidly there.

Hunt around the prep section here on PG too, you get good stuff here too .

PS: Just noticed that you have 95.9 in QA this time. So don't worry about it then ATB

[monsterkartik]

Originally Posted by deep_agrawal

I believe you are incorrect.

Use Euler's to solve this problem:

So, 25^102/17 = 8^102/17.

Now, 8 and 17 are co-primes. Hence, 8^16/17 = 1.

Hence, 8^96/17 = 1.

Now we have 102-96 i.e. 8^6/17 remaining.

Solving this gives 4 as the answer.

A link to solve remainder problems using Euler's:

CAT 2007, CAT 2008, IIM, GMAT, MBA preparation, XAT, problems, math, quant, verbal, data interpretation, reading comprehension, sentence correction, critical reasoning, number system, geometry,

hey deep

i dint get the funda yaar..

actually cant rem of eulers theorem..
can u plzz explain this in bit detail

Cheers

Kartik

[80199]

1 Marks: -0.25/1

Total number of questions = 90.
Section -I [Number of Questions = 30]
Sub-section I-A: [Number of Questions = 10]
Note: Questions I to 10 carry one mark each
Directions for Questions 1 to 5: Answer the questions independently of each other.
If x = (163 + 173 + 183 + 193), then x divided by 70 leaves a remainder of


Choose one answer.
a. 0 b. 1 c. 69 d. 35 incorrect.For any expression of the form a3 + b3 + c3 + d3, it will be exactly divisible by a + b + c + d. Here a + b + c + d = 70, hence the expression is perfectly divisible by 70, and remainder will be 0. A time saver and a visual question.


i got it from somewhere according to me ans should be 12 but this question is showing some other logic? is this logic true

[IIM maniac]

Originally Posted by 80199

1 Marks: -0.25/1

Total number of questions = 90.
Section -I [Number of Questions = 30]
Sub-section I-A: [Number of Questions = 10]
Note: Questions I to 10 carry one mark each
Directions for Questions 1 to 5: Answer the questions independently of each other.
If x = (163 + 173 + 183 + 193), then x divided by 70 leaves a remainder of


Choose one answer.
a. 0 b. 1 c. 69 d. 35 incorrect.For any expression of the form a3 + b3 + c3 + d3, it will be exactly divisible by a + b + c + d. Here a + b + c + d = 70, hence the expression is perfectly divisible by 70, and remainder will be 0. A time saver and a visual question.


i got it from somewhere according to me ans should be 12 but this question is showing some other logic? is this logic true

12 has to be the right answer, i didnt get the other logic and dont think it is ok, suggessions needed from PUYS...

[deep_agrawal]

Originally Posted by monsterkartik

hey deep

i dint get the funda yaar..

actually cant rem of eulers theorem..
can u plzz explain this in bit detail

Cheers

Kartik

Although, I can explain Euler's, I would advice you to go through the link i have posted. The article explains remainder based problems very well.

If u have any more doubts, I can help u clear them.

[dashing]

Originally Posted by 80199

1 Marks: -0.25/1

Total number of questions = 90.
Section -I [Number of Questions = 30]
Sub-section I-A: [Number of Questions = 10]
Note: Questions I to 10 carry one mark each
Directions for Questions 1 to 5: Answer the questions independently of each other.
If x = (163 + 173 + 183 + 193), then x divided by 70 leaves a remainder of


Choose one answer.
a. 0 b. 1 c. 69 d. 35 incorrect.For any expression of the form a3 + b3 + c3 + d3, it will be exactly divisible by a + b + c + d. Here a + b + c + d = 70, hence the expression is perfectly divisible by 70, and remainder will be 0. A time saver and a visual question.


i got it from somewhere according to me ans should be 12 but this question is showing some other logic? is this logic true

even the sum is coming to 712
which when divided by 70 leaves 12 as remainder

[dashing]

Originally Posted by deep_agrawal

I believe you are incorrect.

Use Euler's to solve this problem:

So, 25^102/17 = 8^102/17.

Now, 8 and 17 are co-primes. Hence, 8^16/17 = 1.

Hence, 8^96/17 = 1.

Now we have 102-96 i.e. 8^6/17 remaining.

Solving this gives 4 as the answer.

A link to solve remainder problems using Euler's:

CAT 2007, CAT 2008, IIM, GMAT, MBA preparation, XAT, problems, math, quant, verbal, data interpretation, reading comprehension, sentence correction, critical reasoning, number system, geometry,

yes another silly mistake
need to learn avoiding them

what i meant is 102 is dicisible by 17 so remainder 0
25/17 leaves 8 as remainder
so ans 8
numbers are simple so can be solved by looking at them
though its better to learn and practice eulers theorem