@vbhvgupta said:Q3
:clap:
let rates be x,2x,3x
vivek's share=2/10=1/5
1/5=x*12, x=1/60
so in 8 days, 8*(x+2x+3x)=4/5
OA=c?
edit- you don't need to consider efficiencies at all for this problem, i think!
@vbhvgupta said:we will have to make account to access that content?
yes I think it is a good idea to make an account in TG. we get a lot of good stuff in this site.
I cannot cut and paste the content here due to copyright issues. So would suggest you to make a login and access the content.
ATDH.
@cynara said:let rates be x,2x,3xvivek's share=2/10=1/51/5=x*12, x=1/60so in 8 days, 8*(x+2x+3x)=4/5OA=c?
4/5 
@raopradeep ans is 50 ???????
@vbhvgupta said:@Subhashdec2@Logrhythm@scrabbler@anytomdickandharylast 2 non zero digit of factorial of any number??
@amresh_maverick said:last non zero we got a formula but for last two non zero digit , no idea
last two ka abhi yaad nahi hai....ghar jaake bata dunga...in office right now..
aesi cheezen karke karoge kya waise? ye sabb nahi aayega...but i wld still tell you..
Q 5
@vbhvgupta said:Q 5
28 days?
x/20 + (x + y)/30 + (x + y + z)/60 = 1.....i
x/20 + (x + y + 6)/30 + (x + y + 6)/60 = 1.....ii
1/20 + 1/30 + 1/60 = 1/(x + 6)....iii
solve these 3 eqns..
x = 4,y = 6,z = 18
total days = x + y + z = 28 days
@vbhvgupta said:Q 5
28 days??
let total work be 60 units...
so they working together can complete the work in 10 days...
x+6 = 10
so x = 4..
y+6 = 12
so y = 6
=> 1- 4/10 - 3/10 = 3/10
pramod can complete the remaining 3/10th work in 18 days...
hence total days = 4+6+18 = 28 days...
2guns wer fired from the same place at an interval of 10min.but mohan sitting in the train approaching the place hears the second shot 8mins aftr the 1st.wt is the speed of train if speed of sound is 300m/sec..
18!!!
3r/c=4r/(c+6r)
r and c being the unit cost of a roll and a camera..!!!!
@mailtoankit said:2guns wer fired from the same place at an interval of 10min.but mohan sitting in the train approaching the place hears the second shot 8mins aftr the 1st.wt is the speed of train if speed of sound is 300m/sec..
60mps??
let the distance between the train and that place at the time when mohan heard the sound for the first time be x
so time taken by bullent 1 = x/300
after 10 mins the tain wld hv traveled 600*Vt
so time taken by bullet 2 = {x - (600*Vt)}/300
=> x/300 - {x - (600*Vt)}/300 = 120..
=> x - x + 600*Vt = 300*120
=> Vt = 300*120/600 = 60mps
let the distance between the train and that place at the time when mohan heard the sound for the first time be x
so time taken by bullent 1 = x/300
after 10 mins the tain wld hv traveled 600*Vt
so time taken by bullet 2 = {x - (600*Vt)}/300
=> x/300 - {x - (600*Vt)}/300 = 120..
=> x - x + 600*Vt = 300*120
=> Vt = 300*120/600 = 60mps
@mailtoankit - 75m/s ?
@mailtoankit said:2guns wer fired from the same place at an interval of 10min.but mohan sitting in the train approaching the place hears the second shot 8mins aftr the 1st.wt is the speed of train if speed of sound is 300m/sec..
Distance travelled by train in 8 min= Distance travelled by bullet in 2 min
so x*8=300*2
x=75 m/s..
@Logrhythm said:60mps??
let the distance between the train and that place at the time when mohan heard the sound for the first time be x
so time taken by bullent 1 = x/300
after 10 mins the tain wld hv traveled 600*Vt
so time taken by bullet 2 = {x - (600*Vt)}/300
=> x/300 - {x - (600*Vt)}/300 = 120..
=> x - x + 600*Vt = 300*120
=> Vt = 300*120/600 = 60mps
confused....
@mailtoankit said:2guns wer fired from the same place at an interval of 10min.but mohan sitting in the train approaching the place hears the second shot 8mins aftr the 1st.wt is the speed of train if speed of sound is 300m/sec..
Let train be at a distance of xmand let the speed of the train be S m/s
now for first bullet time taken = x/300 secs - (i)
after 10 mins the train would travel 60*10*s = 600s m
now the total distance = x-600s
so time taken by bullet 2 = x-600s)/300 -(ii)_
since the diff bet the above 2 is 120secs
subtarct (i) and (ii)
we get s = 60m/s
@junefever @mailtoankit
@Jackson1 answer is 60mps
The conceptual mistake which everone is making is considering the distance to be constant,which is not the case.The distance keep on decreasing as the train is moving.
Normal Approach:
10/60=d/300 =>d=50
again,8/60=d/300+x =>x=75
But the approach is wrong- It should be
10/60=d/300 =>d=50
again,8/60=(d-x*(2/60))/(300+x) => x=60