There is a very long line that has been forming all night to

Question

There is a very long line that has been forming all night to buy tickets for a concert. At 7:00 am no more people were allowed to join the line. At 8:00 am two ticket windows opened serving the customers in the line. At 5:00 pm, the last person was done buying his tickets. Assuming the rate that each window helped every customer was the same, how much shorter, in hours, would this process have taken had there been seven more window open all day?

(A) 4 
(B) 5 
(C) 5.5 
(D) 6.5 
(E) 7

venksune · Answer

7. E. 


assume 10m/hr are served per counter. We have 180 peple served in 9 hrs by 2 counters.

If there would have been 9 counters, then all 180 men would hv been served in 2 hrs. Saving 7 hrs.

jimishg · Answer

if we assume that there are 36 ppl in all.

8am to 5 pm has total of 9 hrs in all..


so if there are two windows.. each window will process 2 ppl per hour that 4 ppl hour for both the windows..


so if we keep 7 more windows.... the total windows are 9 now.

so total of 36 ppl at the rate of 2 ppl per window wil be served in 2 hrs. 

therefore 7hrs are saved

Ans : E

Anonymous · Answer

Instead of picking numbers, I treated this as a work problem
Two counters take 18 hrs to complete the work, working at the same rate.
i.e, One counter takes 18 hrs to complete the work. 

Using the work formula 
1/T= 1/A+1/B

1/T=9(1/18) --> Since 9 counters are operating at the same rate

1/T=1/2 => T= 2hrs

Therefore time saved = 9-2= 7 hrs (Ans: E)

There is a very long line that has been forming all night to

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