Machine M, N, O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 1/3 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N? Choose the correct answer:  A) 1/2  B) 1/3  C) 4/13  D) 8/29  E) 6/33
Now ultimately the speed of every machine is given with respect to Mach O.   So lets assume the speed of O, say 12 hrs to make x units (assuming 6 because we can see we will need to divide by 3 and 4   Mach O makes x units in 12 hrs   So, Mach N = 1/3 of O = 1/3*12= 
<gadget id="calculator">1/3*12</gadget>
<output>4</output>
4 hrs to make x units   and Mach M= 3/4 of N = 3/4*4 = 6 hrs to make x units   No they are running simultaneously. Lets see how much each mach makes in 1 hr   Mach O = x/12 units   Mach N = x/4 units   Mach M = x/6 units   In 1 hr, together they make - x/12+x/4+x/6 = x/2   So what ratio of this has Mach N made?   (x/4) / (x/2) = 1/2   1/2ns:1/2=1/2
<result>A</result>
Machine M, N, O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 1/3 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?