Official Quant thread for CAT 2013

jain4444 · December 3, 2012, 10:29am

@veertamizhan said:
Q: I travel three distances in the ration of 1:2:3 at speeds of 20 m/s, 30 m/s amd 40 m/s. If the total time taken is 23 minutes, find the total distance covered.

6x/120 + 8x/120 + 9x/120 = 23*60

23x/120 = 23*60

=> x = 60*120

total distance traveled = 6*60*120 = 43.2 km

@chillfactor sir jii very well explained

mailtoankit · December 3, 2012, 10:31am

@veertamizhan said:
Q: I travel three distances in the ration of 1:2:3 at speeds of 20 m/s, 30 m/s amd 40 m/s. If the total time taken is 23 minutes, find the total distance covered.

43.2 kms?

x/20+2x/30+3x/40=1380

x=7.2 km

6x=43.2km

veertamizhan · December 3, 2012, 10:32am

yes folks, this is my answert too. looks like the book is wrong.

grkkrg · December 3, 2012, 10:33am

@veertamizhan said:
Q: I travel three distances in the ration of 1:2:3 at speeds of 20 m/s, 30 m/s amd 40 m/s. If the total time taken is 23 minutes, find the total distance covered.

43.2 km

t = x/20 + 2x/30 + 3x/40 = 23x/120
t = 23*60 = 1380 seconds

Equating 23x/120 = 23*60
x = 60*120 = 7200 m

Total distance = 6x = 43200m = 43.2 km

veertamizhan · December 3, 2012, 10:38am

If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

krum · December 3, 2012, 10:39am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

4d=60*30/60
d=7.5 km

sowmyanarayanan · December 3, 2012, 10:40am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

7.5 km

deedeedudu · December 3, 2012, 10:41am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

7.5 kms

mailtoankit · December 3, 2012, 10:41am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

x/6-x/10=30/60

x=7.5km

grkkrg · December 3, 2012, 10:41am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

7.5 km

d = 6 * t1
d = 10 * t2
t2 = 0.6 * t1

t1 - t2 = 0.5
0.4 * t1 = 0.5
t1 = 1.25

d = 6 * 1.25 = 7.5 km

pratyush9811 · December 3, 2012, 10:41am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

7.5 KM

jain4444 · December 3, 2012, 10:41am

@veertamizhan said:
If the difference in the time taken to cover a certain distance at 6 kmph and at 10kmph is 30 minutes, find the distance.

10x/60 - 6x/60 = 1/2

4x/60 = 1/2

x = 60/8 = 7.5 km

veertamizhan · December 3, 2012, 10:44am

I am horrible at math. Any suggestions?

pratyush9811 · December 3, 2012, 10:47am

@veertamizhan cover the basics and Practice!!

jain4444 · December 3, 2012, 10:48am

@veertamizhan said:
I am horrible at math. Any suggestions?

you got the right place then

just be regular on this thread

Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:
A. 10 B. 12
C. 14 D. 16

krum · December 3, 2012, 10:51am

@jain4444 said:
you got the right place then just be regular on this thread Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:A. 10 B. 12C. 14 D. 16

(a+b+c)*6=100

given

(a+b+c)*2 + (a+b)*7=100

==>(a+b)=200/21

=>c=100/6-200/21=300/42=100/14

14 hours

deedeedudu · December 3, 2012, 10:53am

@jain4444 said:
you got the right place then just be regular on this thread Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:A. 10 B. 12C. 14 D. 16

14 hrs

pratyush9811 · December 3, 2012, 10:53am

@jain4444 said:
you got the right place then just be regular on this thread Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:A. 10 B. 12C. 14 D. 16

14 HR.

grkkrg · December 3, 2012, 10:55am

@jain4444 said:
you got the right place then just be regular on this thread Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:A. 10 B. 12C. 14 D. 16

C.14?

1/A + 1/B + 1/C = 1/6
After 2 hours => 2/6 = 1/3 of the tank is filled

1/A + 1/B = 1/7 * 2/3 = 2/21

1/C = 1/6 - 2/21 = 7/42 - 4/42 = 3/42 = 1/14

C takes 14 hours to fill the tank.

sowmyanarayanan · December 3, 2012, 10:56am

@jain4444 said:
you got the right place then just be regular on this thread Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:A. 10 B. 12C. 14 D. 16

Total work = 42 units

a + b + c = 7 units/hour

after 2 hours, 28 units remaining, which is completed by a+b in 7 hours.

so a + b = 4

so c = 3

hence c can complete in 14 hours