If
*Jon can do a piece of work in 10 days,
*Sam can do it in 15 days and
*Pip can do it in 30 days,
how many days will it take if all the three of them work together to complete it?
Note: Assume average rates!!!
If
*Jon can do a piece of work in 10 days,
*Sam can do it in 15 days and
*Pip can do it in 30 days,
how many days will it take if all the three of them work together to complete it?
Note: Assume average rates!!!
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 | ||
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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 |
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Perfect!
Try this (a tricky question):
/forum/a-very-tricky-question-very-short-one--231062.asp#.UMm4YOQ3vpw
| Originally posted by : raunak | ||
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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. |
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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 similar to mohd rafis' solution....just dat he calculated work done by each person in 1 day.....and i calculated each persons efficiency,.
CAclubindia
