in 5 days . is it right?????

  5 days

days                     10                  15                   30 

km/day                30                   20                    10

total km             300                   300                   300

Total km of all three 30+20+10=60

Total km needs to cover 300

Days required  300/60= 5 

Its 5 days, u are very correct harshita

plz explian the logic of 5days??

 (10 -.99) = 9days

Takin Jon as the base..10 days are minimum reqd to complete the work...so Johns efficiency is 100%,
sam efficiency is 10/15*100=66.67%
Pip efficiency= 10/30*=33.33%
 

so if they all work together..average efficiency of each person = (100+66.67+33.33)/3=66.67%

So therefore if they all work together they wud require 15 days to complete on average by 1 person....so if they all work together,,,,

its 15/3=5 days.

J work in 1 day 1/10

S work in 1 day 1/15

P work in 1 day 1/30

All works in 1 day 1/10+1/15+1/30=6/30=1/5

All complete the work in 5 days

Jon  alone can complete it in 10 days.

Then how can it be above 10 if they work altogether !

jon completes the work in one day 1/10
Sam completes the work in one day 1/15
Pip completes thew work in one day 1/30
If all work together in one day they will complete 1/10+1/15+1/30 = 1/5
If they complete 1/5 of work in one fay working together they can complete the work in 5 days

Originally posted by : Md. Rafi
	J work in 1 day 1/10 S work in 1 day 1/15 P work in 1 day 1/30 All works in 1 day 1/10+1/15+1/30=6/30=1/5 All complete the work in 5 days

Perfect!

Try this (a tricky question):

/forum/a-very-tricky-question-very-short-one--231062.asp#.UMm4YOQ3vpw

Originally posted by : raunak
	Takin Jon as the base..10 days are minimum reqd to complete the work...so Johns efficiency is 100%, sam efficiency is 10/15*100=66.67% Pip efficiency= 10/30*=33.33%   so if they all work together..average efficiency of each person = (100+66.67+33.33)/3=66.67% So therefore if they all work together they wud require 15 days to complete on average by 1 person....so if they all work together,,,, its 15/3=5 days.

Dear Raunak,

I didn't get you! I guess its pretty complicated!

So could you please elucidate your working!

These kinds of Questions were asked in 8th Standard.

:D

Answer is 5

Everyone here knows that

its 5 days ...

Its similar to mohd rafis' solution....just dat he calculated work done by each person in 1 day.....and i calculated each persons efficiency,.