Two identical machines have the ability to produce both nuts and bolts. However, it takes 1 second to produce a bolt but 2 seconds to produce a nut. What is the fastest the two machines, working together, can produce 1,200 nuts and 1,200 bolts?  Select:
A) 1,250 seconds
B) 1,500 seconds
C) 1,800 seconds
D) 2,000 seconds
E) 3,000 seconds
I used the Rate formula (R=\frac{1}{T})   Rate of 1st machine = Rate of making 1 bolt + Rate of making 1 nut = 1 + \frac{1}{2}   Rate of 1st machine = Rate of 2nd machine   After this I got lost.   Please can you help how to approach using algebra?   I wouldn't complicate:   1 machine needs 1,200*1 seconds to produce 1,200 bolts, so 2 need half of that, so 1,200/2 seconds.=600 sec   1 machine needs 1,200*2 seconds to produce 1,200 nuts, so 2 need half of that, so 1,200*2/2 seconds.=1200 sec   total = 1800   1,800 seconds
<result>C</result>
Two identical machines have the ability to produce both nuts and bolts. However, it takes 1 second to produce a bolt but 2 seconds to produce a nut. What is the fastest the two machines, working together, can produce 1,200 nuts and 1,200 bolts?