Latest Elitmus Aptitude Question SOLUTION: A finishes a work in 8 hrs,B finishes a work in 10 hrs,C finishes a work in 12 hrs.A,B,C work together but A leaves after 2 hrs find the time t taken by B & C?

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(#M40038906) ELITMUS Numerical Ability question numerical Keep an EYE

A finishes a work in 8 hrs,B finishes a work in 10 hrs,C finishes a work in 12 hrs.A,B,C work together but A leaves after 2 hrs find the time t taken by B & C?

Asked In Elitmus S B HARISH (9 years ago)

Unsolved Read Solution (9)

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Read Solution (9) :

shilpy  (9 years ago)

A's 1 hour work =1/8
B's 1 hour work=1/10
c's 1 hour work=1/12
(A+B+C)'s 2 hour work=2*(1/8+1/10+1/12)=37/60
remaining work=1-37/60=23/60
(B+c)'s 1 hour work=(1/10+1/12)=11/60
therefore time taken by B and C=23/60*60/11=23/11hrs

Is this solution Helpfull? Yes (54) | No (1)  

Pranoy Bej  (9 years ago)

A+B+C=1/8+1/10/+1/12=37/120
B+c=22/120
after 2 hour A leaves.
remaining work=1-(2*37/120)=46/120
B+C can do 46/120 in (46/120)*(120/22)=23/11 hour

Is this solution Helpfull? Yes (4) | No   

DIMPLE SINGH  (9 years ago)

sorry this is the rit ans
if A ,B and C working together then in 1hr , work done by them ..
(1/10)+(1/8)+(1/12) = 37/120
in 2 hrs work done by them will be = 74/120
remaining work= 1- 74/120 = 46/120 = 23/60
work done by B&C in 1 hr = (1/10)+(1/12)= 11/60
to do 23/60 B&C require = 23/11 hrs

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DIMPLE SINGH  (9 years ago)

if A ,B and C working together then in 1hr , work done by them ..
(1/10)+(1/8)+(1/12) = 37/120
in 2 hrs work done by them will be = 54/120=27/60
remaining work= 1-(27/60)=33/60

if B and C are working together then work done by them in 1 hr is
(1/10)+(1/12)= 11/60

to do 11/60 B&C require = 1 hr
to do 33/60 B&c require = 3 hrs

Is this solution Helpfull? Yes (1) | No (8)  

veer kumar  (9 years ago)

there is a slight mistake in this question i.e"A left the work 2 hours before the completion of the work"

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kummari venkatesh  (9 years ago)

B&C TAKE 2HOURS TO COMPLETE THE REMAINING WORK
TAKE LCM OF 8,10,12 SO WE GET TOTAL UNITS OF WORK AS 120UNITS
SO
A---120/8=15UNITS/HR
B----120/10=12UNITS/HR
C-----120/12=10UNITS/HR
THEY WORK TOGETHER FOR 2HOURS SO TOTAL WORK COMPLETED WAS 15*2+12*2+10*2=74UNITS
REMAINING WORK=120-74=44UNITS
SO B=12UNITS/HR
C=10UNITS/HR
---------------
B&C=22UNITS/HR so to complete r.w i.e 44units they will take 2hours

Is this solution Helpfull? Yes (1) | No (3)  

aman anurag  (9 years ago)

1/8+1/10+1/12=37/120(combine 1 hour work)
all tree worked for 2 hours so
work done in 2 hour=74/120=37/60
Remaining work=23/60
B and C 1 hour work =1/10+1/12=11/60
(23/60)/(11/60)=23/11 hour

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payal   (9 years ago)

2.09 hours

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Sourav sarkar  (9 years ago)

23/11 hrs.

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