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Machine A, working alone at its constant rate, manufactures 280 bolts
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05 Jul 2018, 01:43
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Machine A, working alone at its constant rate, manufactures 280 bolts per hour, and machine B, working alone at its constant rate, manufactures 220 bolts per hour. How many hours will it take for machines A and B, working together at their respective constant rates,to manufacture 1,000 bolts? A. 1 B. 1.3 C. 1.5 D. 1.8 E. 2
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Re: Machine A, working alone at its constant rate, manufactures 280 bolts
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05 Jul 2018, 01:51
Bunuel wrote: Machine A, working alone at its constant rate, manufactures 280 bolts per hour, and machine B, working alone at its constant rate, manufactures 220 bolts per hour. How many hours will it take for machines A and B, working together at their respective constant rates,to manufacture 1,000 bolts?
A. 1 B. 1.3 C. 1.5 D. 1.8 E. 2 In 1 hour A and B will make 220+280 bolts. Thus, in one hour total of 500 bolts are produced. For 1000 bolts, 2 hours would be required. Answer: E Posted from my mobile device
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Machine A, working alone at its constant rate, manufactures 280 bolts
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05 Jul 2018, 06:17
Bunuel wrote: Machine A, working alone at its constant rate, manufactures 280 bolts per hour, and machine B, working alone at its constant rate, manufactures 220 bolts per hour. How many hours will it take for machines A and B, working together at their respective constant rates,to manufacture 1,000 bolts?
A. 1 B. 1.3 C. 1.5 D. 1.8 E. 2 Rate of manufacturing of machine A=280 bolts per hour Rate of manufacturing of machine B=220 bolts per hour Combined rate*time=Work done or, (280+220)bolt/hour*time=1000 bolts Or, Time=\(\frac{1000}{500}\)=2 hours Ans. E
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Re: Machine A, working alone at its constant rate, manufactures 280 bolts
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05 Jul 2018, 07:26
Bunuel wrote: Machine A, working alone at its constant rate, manufactures 280 bolts per hour, and machine B, working alone at its constant rate, manufactures 220 bolts per hour. How many hours will it take for machines A and B, working together at their respective constant rates,to manufacture 1,000 bolts?
A. 1 B. 1.3 C. 1.5 D. 1.8 E. 2 Since the efficiency of both the machines are given it boils down to  \(\frac{1000}{(220 + 280)} = 2\) Hours, Answer must be (E)
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Re: Machine A, working alone at its constant rate, manufactures 280 bolts
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07 Jul 2018, 18:31
Bunuel wrote: Machine A, working alone at its constant rate, manufactures 280 bolts per hour, and machine B, working alone at its constant rate, manufactures 220 bolts per hour. How many hours will it take for machines A and B, working together at their respective constant rates,to manufacture 1,000 bolts?
A. 1 B. 1.3 C. 1.5 D. 1.8 E. 2 Since the combined rate is 500 bolts per hour, then it will take 1,000/500 = 2 hours for the two machines to manufacture 1,000 bolts. Answer: E
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