Mr P Mr Q and Mr R takes a project and they can complete in 36 hours 54 hours and

Assume that the project has to be completed in X hours.
So R has worked for X hours.

Since P has left 8 hours before completion, he worked for X - 8 hours and
Q had left 12 hours before, his participation in work is for X - 12 hours.

Therefore (X - 8) + (X - 12) + X = 1(completion of project)
P can complete a project in 36 hours.
In (X - 8) hours P can complete = (X - 8) / 36

Similarly, Q can complete a project in 54 hours.
In (X - 12) hours P can complete = (X - 12) / 54

In X hours R can complete = X / 72

(X - 8) / 36 + (X - 12) / 54 + X / 72 = 1
6 (X - 8) + 4(X - 12) + 3X = 216
13X = 312
X = 24
Hence the required answer is 24 hours.
10 years agoHelpfull: Yes(69) No(2)

(x-8)/36+(x-12)/54+x/72=1
12(x-8)+8(x-12)+6x=432
x=24
10 years agoHelpfull: Yes(11) No(4)
let us take lcm of time taken by p,q,r that is 216 work now find per hour work , that is p= 216/36=6 similarly for q=4work per hour and r= 3 work per hour now taking option to satisfy condition takin a that is 24 so for first 12 hour all work togather thats is adding every one per day work
6+4+3= 13 ,13*12 =156 work now after this q left noe p and r work together so 6+3=9 so for next 4 days 9*4=36 noe for rest 8 day only r will work . so 8*3=24 adiing all work 156+36+24=216 so total work = calculated work so this is correct answer .
10 years agoHelpfull: Yes(9) No(0)
Assume that the project has to be completed in X hours.
So R has worked for X hours.

Since P has left 8 hours before completion, he worked for X - 8 hours and
Q had left 12 hours before, his participation in work is for X - 12 hours.

Therefore (X - 8) + (X - 12) + X = 1(completion of project)
P can complete a project in 36 hours.
In (X - 8) hours P can complete = (X - 8) / 36

Similarly, Q can complete a project in 54 hours.
In (X - 12) hours P can complete = (X - 12) / 54

In X hours R can complete = X / 72

(X - 8) / 36 + (X - 12) / 54 + X / 72 = 1
6 (X - 8) + 4(X - 12) + 3X = 216
13X = 312
X = 24
Hence the required answer is 24 hours.
10 years agoHelpfull: Yes(2) No(3)
Assume that the project has to be completed in X hours.
So R has worked for X hours.

Since P has left 8 hours before completion, he worked for X - 8 hours and
Q had left 12 hours before, his participation in work is for X - 12 hours.

Therefore (X - 8) + (X - 12) + X = 1(completion of project)
P can complete a project in 36 hours.
In (X - 8) hours P can complete = (X - 8) / 36

Similarly, Q can complete a project in 54 hours.
In (X - 12) hours P can complete = (X - 12) / 54

In X hours R can complete = X / 72

(X - 8) / 36 + (X - 12) / 54 + X / 72 = 1
6 (X - 8) + 4(X - 12) + 3X = 216
13X = 312
X = 24
Hence the required answer is 24 hours.
10 years agoHelpfull: Yes(2) No(0)
(x-8)/36+(x-12)/54+x/72=1
12(x-8)+8(x-12)+6x=432
x=24
9 years agoHelpfull: Yes(1) No(0)
Let x be the total hour taken by r to complete the work
p 36 - 6 WORK/HOUR
q 54 LCM (216) -4 WORK/HOUR
r 72 -3 WORK/HOUR

here 216 is the total work

p works for (x-8)hours
q works for (x-12)hours
r works for (x)hours

thus
6*(x-8)+4*(x-12)+3*x=216

after solving this equation
we get x=24

hence ans is 24
9 years agoHelpfull: Yes(1) No(0)
42 is the answer....
10 years agoHelpfull: Yes(0) No(19)
24 is the ans
10 years agoHelpfull: Yes(0) No(1)
(x-8)/36+(x-12)/54+x/72=1
6(x-8)+4(x-12)+3x=216
6x-48+4x-48+3x=216
13x=312
x=24
ana:a
10 years agoHelpfull: Yes(0) No(0)
let xhrs be the time for completion of work
then,p's 1hr work->1/36 & he works for x-8 hrs
q's 1hr work->1/54 & he works for x-12 hrs
r's 1hr work->1/72 & he works for x hrs

(x-8)/36+(x-12)/54+x/72=1

so ans is x= (a) 24
9 years agoHelpfull: Yes(0) No(0)
x-8/36 + x-12/54 + x/72 = 1
so x= 24 hrs
9 years agoHelpfull: Yes(0) No(0)
X(1/36+1/54+1/72)+8(1/54+1/72)+1/12(1/36+1/72)=1
SOLVE FOR X
X=4
SO R WORKED FOR 4+8+12=24 HRS
8 years agoHelpfull: Yes(0) No(0)

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