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 1,400 nuts and 1,400 bolts?	Choose the correct answer:
A) 1,250 seconds
B) 1,500 seconds
C) 1,750 seconds
D) 2,100 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 1,400*1 seconds to produce 1,400 bolts, so 2 need half of that, so 1,400/2 seconds.=700   1 machine needs 1,400*2 seconds to produce 1,400 nuts, so 2 need half of that, so 1,400*2/2 seconds.=1400   total = 2100 sec   2,100 seconds
<result>D</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 1,400 nuts and 1,400 bolts?