Official Quant thread for CAT 2013

MBA CAT 2024
24328
@mailtoankit said:
yeh diff. question hai....dec by 25%...usme 75% dec tha...
my bad..
thanks for correctin..
24329
@Narci said:
is the OA for the 2nd one correct? most of us are gettin 2592..
this is a different question ..
2592 is correct for the previous ques. :)
24330

sab saath me bol pade..

24331
@amresh_maverick said:
1> A 3 digit no xyz is a perfect square. No of factors is also a perfect suqare. If x+y+z is also a perfect square , what is the no of factors of 6 digit no xyzxyz ?
Multiple answers hai kya? Options de do....ek mil gaya...

regards
scrabbler
24332
@amresh_maverick said:
1> A 3 digit no xyz is a perfect square. No of factors is also a perfect suqare. If x+y+z is also a perfect square , what is the no of factors of 6 digit no xyzxyz ?
196 is xyz? 196196 = 1001*2^2*7^2 = 11*13*7^3*2^2 no. of factors = 48
there can be more such numbers but ans should be same i guess because the difference is just about 101... @scrabbler
24333
@amresh_maverick said:
1> A 3 digit no xyz is a perfect square. No of factors is also a perfect suqare. If x+y+z is also a perfect square , what is the no of factors of 6 digit no xyzxyz ?
72 ?
24334
@pratskool said:
196 is xyz? 196196 = 101*2^2*7^2 no. of factors is 18 ?? there can be more such numbers but ans should be same i guess because the difference is just about 101...
225, 900? But then x, y, z not distinct so shayad not to count them?

regards
scrabbler
24335
@pratskool said:
196 is xyz? 196196 = 101*2^2*7^2 no. of factors is 18 ?? there can be more such numbers but ans should be same i guess because the difference is just about 101... @scrabbler
yaar 101 hai ya 1001 ?
24336
@pratskool said:
196 is xyz? 196196 = 101*2^2*7^2 no. of factors is 18 ?? there can be more such numbers but ans should be same i guess because the difference is just about 101... @scrabbler
1001 hai and so the difference will vary....because 1001 includes a 7...

@Narci

regards
scrabbler
24337
@amresh_maverick said:

2> A no N when increased by 50% has its no of factors as unchanged . But when decreased by 25% , the no of factors is decreased by 33.33%. Min value of N ?
@scrabbler @ChirpiBird @saurav205 Mujhe ye wala question kaise solve karte hai koi sikha do pls
24338
@Narci said:
yaar 101 hai ya 1001 ?
haan 1001 hoga sorry...
24339
@amresh_maverick said:
1> A 3 digit no xyz is a perfect square. No of factors is also a perfect suqare. If x+y+z is also a perfect square , what is the no of factors of 6 digit no xyzxyz ?
100 , 196 ....?

100 = 2^2*5^2
no. of factors = 3*3 = 9
1 + 0 + 0 = 1
100100 = 2^2*5^2*7*11*13 = 3*3*2*2*2 = 72 ??

196 = 2^2*7^2
no. of factors = 3*3 = 9
1 + 9 + 6 = 16
196196 = 2^2*7^3*11*13 = 3*4*2*2 = 48 ??

kaise karna hai ??
24340
Enough of number system :)

A boy goes from his house to his school daily by a motorbike. He drives the motorbike at three different speeds 'a', '2.5a' and '4a' km/hr for three different durations during the journey. He definitely knows the time intervals for which he should drive his motorbike at each of these speeds so as to reach the school on time.

On one particular day he starts 20 minutes late from his house and hence the extra time for which he drives his motorbike at '2.5a' km/hr is 6 minutes. Find the extra time for which he drives at '4a' km/hr to reach the school on time.
24341
@amresh_maverick said:
Enough of number system A boy goes from his house to his school daily by a motorbike. He drives the motorbike at three different speeds 'a', '2.5a' and '4a' km/hr for three different durations during the journey. He definitely knows the time intervals for which he should drive his motorbike at each of these speeds so as to reach the school on time.On one particular day he starts 20 minutes late from his house and hence the extra time for which he drives his motorbike at '2.5a' km/hr is 6 minutes. Find the extra time for which he drives at '4a' km/hr to reach the school on time.
11/3?

(20 - 6*1.5)/3

regards
scrabbler
24342
Single copy of a book costs $16, but purchasers of 20 copies or more pay only $13 per copy. How many values of 'n' (0
24343
@amresh_maverick said:
Enough of number system A boy goes from his house to his school daily by a motorbike. He drives the motorbike at three different speeds 'a', '2.5a' and '4a' km/hr for three different durations during the journey. He definitely knows the time intervals for which he should drive his motorbike at each of these speeds so as to reach the school on time.On one particular day he starts 20 minutes late from his house and hence the extra time for which he drives his motorbike at '2.5a' km/hr is 6 minutes. Find the extra time for which he drives at '4a' km/hr to reach the school on time.
t minutes he drives extra at 4a speed..
so he drives with speed a for 20 + 6 +t mins less than usual
total distance will be same
2.5a*6+4at=(26+t)a
26-15=3t
t=11/3 mins
24344
@Narci said:
72 ?
@amresh_maverick said:
1> A 3 digit no xyz is a perfect square. No of factors is also a perfect suqare. If x+y+z is also a perfect square , what is the no of factors of 6 digit no xyzxyz ?
OA: 72

plz share detail soln
24345
@amresh_maverick said:
Single copy of a book costs $16, but purchasers of 20 copies or more pay only $13 per copy. How many values of 'n' (0
for 20 books cost = 260
for n copies n*16, now n*16 > 260... 17,18,19 3 such value exists,,, the problem cant be so easy, perhaps m making a mistake
24346
@amresh_maverick said:
Single copy of a book costs $16, but purchasers of 20 copies or more pay only $13 per copy. How many values of 'n' (0
3 values ??
16n > 260..
n = 17,18,19
24347
@amresh_maverick said:
Single copy of a book costs $16, but purchasers of 20 copies or more pay only $13 per copy. How many values of 'n' (0
17,18,19 ??...so 3 such values of n ?
20*13 = 260
19*16 = 304
18*16 = 288
17*16 = 272
16*16 = 256