Official Quant thread for CAT 2013

@maroof10 said:
If the value of a purchase is less than rs 3200,the customer gets a discount of 14%.The customer gets a discount of 16% on a purchase between rs 3200-6300.The customer gets a discount of certain % on a purchase above rs 6300.A customer gets a total discount of rs 1520 which is equal to 16% of the purchase value.How much discount does the customer get for amount exceeding rs 6300?

18?
@abhishek.2011 said:
it can be 120
bhai samjha do
@albiesriram said:
OA:-


@vbhvgupta said:
IF the eqnx^5 + 15x^4 + 85x^3 + 225x^2 + 274x +a - 119 = 0 has exactly 5 negative roots then the value of a can be1008512090
-(a - 119)
a - 119 >0
a can be 120

@albiesriram said:
it will be
(1+k^2)^3/k^2
@albiesriram said:
it will be 104

1/2 * 2/3*13 *2/3 *12*3=104
@vbhvgupta said:
bhai samjha do
bhai just focus on productof the roots
it is abcde=-(a-119)
so abcde= 119-a
now as all roots are negative so 119-a has to be negative which is possible only for a=120 from given options so 120
@albiesriram said:
c. [(1+k^2)^3]/k^2
@albiesriram said:
PR=3x

MQ*PR=RQ*PQ
MQ=2sqrt(2)x/3

PM=8x/3

2sqrt(2)/1??
@albiesriram said:
option 1?

Q -- There are 42 students in a hostel, Due to admission of 13 new students, the expense of the mess increases by Rs 31. per day. While the average expenditure per head diminished by Rs 3. What was the original Expenditure of the mess ?

ANs - 633.23

Please Tell the approach !

@albiesriram said:
2_/2 : 1 ?
@albiesriram said:
Option 1
OA:-



@albiesriram said:
2rt2/1?
@ananyboss said:
Q -- There are 42 students in a hostel, Due to admission of 13 new students, the expense of the mess increases by Rs 31. per day. While the average expenditure per head diminished by Rs 3. What was the original Expenditure of the mess ?ANs - 633.23Please Tell the approach !
x+31/55 =x/42 -3
31/55 +3 =x/42 -x/55
196/55 = 13x/55*42
196*42/13 =x
x=633.23
@albiesriram said:
it will be 2_/2:1
option a
@ananyboss said:
Q -- There are 42 students in a hostel, Due to admission of 13 new students, the expense of the mess increases by Rs 31. per day. While the average expenditure per head diminished by Rs 3. What was the original Expenditure of the mess ?ANs - 633.23Please Tell the approach !
let price be x
before mess cost will be 42x

after 13 students came.. 42x + 31
or in terms of avg, 55(x-3)
both are equal
42x + 31 = 55(x-3)
x=15.076


so before mess cost was 42*x = 633.23