@anytomdickandhary said:how did you get the inequality.... I could not really understand your solution can you please elaborate a bit?ATDH.
wil be quad in n .. so for real n , D>0.and that exp in form 121k .
@krum said:For how many integers 'm' is m^3-8m^2+20m-13 a prime number ?
m^3-8m^2+20m-13
= (m-1)(m^2-7m-13)
= (m-1)((m-3)(m-4) + 1)
For it to be prime.. either 1st has to 1 or second
Hence m=2,3 or 4
3 values
@sujamait said:wil be quad in n .. so for real n , D>0.and that exp in form 121k .
Sorry to bother you again!
I understood this part
9 >= 4.1.(5-121k)
9 >= 20 - 484k
484k >= 11
But unable to comprehend the below part.
K=1/11 only will satisfy
but,n^2+3n+5 = 11
n^2+3n = 6
no integer satisfy
can you please elaborate on this part please.
Anyone else who can help me with the explanation is welcome.
ATDH.
find the number of number between 1 to 700 which are divisible by 2 or 3 but not by 7?
any one please tell me
@IIM-A2013 said:find the number of number between 1 to 700 which are divisible by 2 or 3 but not by 7?any one please tell me
168?
how to solve this?
every day neeras husband meets her at the city railway station at 6 pm and driver her to their residence. one day she left early from office and reached the railway station at 5 pm. She started walking to her home and met her husband coming from their residence on the way and they reached home 10 mins earlier than usual. for how long did she walk?>
a)1hr b)50min c)1/2hr d)55min
@hxparam said:how to solve this?every day neeras husband meets her at the city railway station at 6 pm and driver her to their residence. one day she left early from office and reached the railway station at 5 pm. She started walking to her home and met her husband coming from their residence on the way and they reached home 10 mins earlier than usual. for how long did she walk?>a)1hr b)50min c)1/2hr d)55min
55min?
@gautam22 said:A tank of ht. 3h has and inlet pipe A and two outlet pipes B and C at heights 2h and h from the base.A can fill tank in 12 hrs. The time in which B and C can empty it are in the ratio 1:2. All the pipes are opened simultaneously. The tank is filled in 16 hrs 48 mins. Find the time in which B can empty it?24273036
3h*1008/720-3h=192*3h/x+576*3*3h/x
=>3*288/720=3*192/x+3*9*192/x
=>x=10*192*720/288
=>x=4800 min or 80 hrs
so B can in 40 hrs
answer kya hai yaar?
=>3*288/720=3*192/x+3*9*192/x
=>x=10*192*720/288
=>x=4800 min or 80 hrs
so B can in 40 hrs
answer kya hai yaar?
@hxparam said:how to solve this?every day neeras husband meets her at the city railway station at 6 pm and driver her to their residence. one day she left early from office and reached the railway station at 5 pm. She started walking to her home and met her husband coming from their residence on the way and they reached home 10 mins earlier than usual. for how long did she walk?>a)1hr b)50min c)1/2hr d)55min
husband saved 5 min while going towards station, which means it was 5:55 when they met
so she was walking for 55 min
so she was walking for 55 min
@IIM-A2013 said:find the number of number between 1 to 700 which are divisible by 2 or 3 but not by 7?any one please tell me
by 2 - 700/2=350
by 3 - 700/3=233
by both - 700/6-116
by 2 and 7 - 700/14=50
by 3 and 7 - 700/21=33
by 2,3 and 7 - 700/42=16
350+233-116-(50+33-16)
=400
by 3 - 700/3=233
by both - 700/6-116
by 2 and 7 - 700/14=50
by 3 and 7 - 700/21=33
by 2,3 and 7 - 700/42=16
350+233-116-(50+33-16)
=400
@hxparam said:how to solve this?every day neeras husband meets her at the city railway station at 6 pm and driver her to their residence. one day she left early from office and reached the railway station at 5 pm. She started walking to her home and met her husband coming from their residence on the way and they reached home 10 mins earlier than usual. for how long did she walk?>a)1hr b)50min c)1/2hr d)55min
55min
@gautam22 said:sir ye aapne kya approach lagayi hai?
A can fill it in 12 hrs, so extra work = 1008/720-1
this is equal to work done by B and C
for the first 4 hours only A is working, after that for 1008-240=768 minutes B and C come into play
B is 2 times faster than C
so C alone works for 768/4 minutes and B and C work for 768*3/4 minutes
if C can empty it in x minutes, in 192 min 192*3h/x work
B and C can empty it in x/3 minutes, in 576 min 576*3h*3/x work
now i equated both
this is equal to work done by B and C
for the first 4 hours only A is working, after that for 1008-240=768 minutes B and C come into play
B is 2 times faster than C
so C alone works for 768/4 minutes and B and C work for 768*3/4 minutes
if C can empty it in x minutes, in 192 min 192*3h/x work
B and C can empty it in x/3 minutes, in 576 min 576*3h*3/x work
now i equated both
@hxparam said:how to solve this?every day neeras husband meets her at the city railway station at 6 pm and driver her to their residence. one day she left early from office and reached the railway station at 5 pm. She started walking to her home and met her husband coming from their residence on the way and they reached home 10 mins earlier than usual. for how long did she walk?>a)1hr b)50min c)1/2hr d)55min
10 mins is saved in both directions
So in 1 direction 5 mins r saved
Hence Neeras walked for 55 mins
So in 1 direction 5 mins r saved
Hence Neeras walked for 55 mins
@IIM-A2013 said:find the number of number between 1 to 700 which are divisible by 2 or 3 but not by 7?any one please tell me
Nos divisible by 2
699/2=349
Nos divisible by 3
699/3=233
Both 699/6=116
Total=349+233-116=466
Nos divisible by 14
699/14=49
By 21=699/21=33
By 2 and 3 and 7
699/42=16
Total=466-(49+33-16)=400
699/2=349
Nos divisible by 3
699/3=233
Both 699/6=116
Total=349+233-116=466
Nos divisible by 14
699/14=49
By 21=699/21=33
By 2 and 3 and 7
699/42=16
Total=466-(49+33-16)=400
@IIM-A2013 said:find the number of number between 1 to 700 which are divisible by 2 or 3 but not by 7?any one please tell me
400??
233+349-116-(49+33-16)=400
@gautam22 said:A tank of ht. 3h has and inlet pipe A and two outlet pipes B and C at heights 2h and h from the base.A can fill tank in 12 hrs. The time in which B and C can empty it are in the ratio 1:2. All the pipes are opened simultaneously. The tank is filled in 16 hrs 48 mins. Find the time in which B can empty it?24273036
Let the capacity be 36
Then rate of A=3 lts/hr
B---36/x,C----36/2x
Total time is (16+4/5) hrs
For upto h height (12 lts) no outlet pipe is working
hence it takes 4 hrs
After that for the next 12 lts
12/(3-36/2x)
And last 12 lts
12/(3-(36/2x+36/x))
Add all
4+12/(3-36/2x)+12/(3-(36/2x+36/x))=(16+4/5)
x=36
Then rate of A=3 lts/hr
B---36/x,C----36/2x
Total time is (16+4/5) hrs
For upto h height (12 lts) no outlet pipe is working
hence it takes 4 hrs
After that for the next 12 lts
12/(3-36/2x)
And last 12 lts
12/(3-(36/2x+36/x))
Add all
4+12/(3-36/2x)+12/(3-(36/2x+36/x))=(16+4/5)
x=36
@gautam22 said:sir jaise aapne kara hai vaise to agar capacity "n" loge to "n" aayega ans
Is it so? Then check with capacity 24 is it giving 24 as ans?
@gautam22 said:A tank of ht. 3h has and inlet pipe A and two outlet pipes B and C at heights 2h and h from the base.A can fill tank in 12 hrs. The time in which B and C can empty it are in the ratio 1:2. All the pipes are opened simultaneously. The tank is filled in 16 hrs 48 mins. Find the time in which B can empty it?24273036
let C can empty the tank in x hrs
work done by A and C in 1 hr = (x-12)/12x
work done by A,B and C in 1 hr = (x-36)/12x
A does 1/3 of the work in first 4 hours, so time left= 12hrs 48mins= 768/60 hrs
This time is divided into work between {A and C}, and {A,B and C}.
as {A and C} does more work, less time would be spent here, i.e (x-36)/(x-12+x-36)
=(x-36)/(2x-48)*768/60
as {A,B and C} does less work, more time would be spent here, i.e (x-12)/(x-12+x-36)
=(x-12)/(2x-48)*768/60
so
2/3=(x-12)/12x*768/60*(x-36)/(2x-48) + (x-36)/12x*768/60*(x-12)/(2x-48)
x=72
so 36 hrs
@gautam22 said:yes sir...
Yaar mera to isse b 36 a raha.
Rate of A in this case 2lts/hr ho jaega
4+8/(2-24/2x)+8/(2-24/2x-24/x)=16+4/5
Solve kar k dekh lo dost 36 hi a raha
directly x=36 put kar lo nd check
Rate of A in this case 2lts/hr ho jaega
4+8/(2-24/2x)+8/(2-24/2x-24/x)=16+4/5
Solve kar k dekh lo dost 36 hi a raha
directly x=36 put kar lo nd check