Combined Rate of Nail-Producing Machines Welcome! You are encouraged to register with the site and login (for free). When you register, you support the site and your question history is saved.Machine A produces nails at a uniform rate of 120 every 10 seconds, and Machine B produces nails at a uniform rate of 100 every 15 seconds. If the two machines run simultaneously, how many seconds will it take for them to produce a total of 140 nails? 7.0 7.5 8.0 8.5 9.0 Review Answer