Machine A can process 6000 envelopes in 3 hours. Machines B and C working together but independently can process the same number of envelopes in 2.5 hours. If Machines A and C working together but independently process 3000 envelopes in 1 hour, then how many hours would it take Machine B to process 9800 envelopes.
Select the correct option.
A) 2
B) 3
C) 4
D) 6
E) 7
You can either take the amount of work done as the same as Karishma has done or take the work done by each in the same time. I will do the latter   1. Work done in 1 hr by A is 2000 envelopes   2. Work done in 1 hr by A and C is 3000 envelopes   3. So work done in 1 hr by C is 1000 envelopes   4. Work done in 1 hr by B and C is 2400 envelopes   5. So work done in 1 hr by B is 1400 envelopes   6. So to process 9800 envelopes B will take   9800/1400= 
<gadget id="calculator">  9800/1400</gadget>
<output>7</output>
7 hrs   So the answer is choice 7
<result>E</result>
Machine A can process 6000 envelopes in 3 hours. Machines B and C working together but independently can process the same number of envelopes in 2.5 hours. If Machines A and C working together but independently process 3000 envelopes in 1 hour, then how many hours would it take Machine B to process 9800 envelopes.