A queue of trucks at a crusher plant hopper is known...

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A queue of trucks at a crusher plant hopper is known to be M/M/1 queue. The probability that there is no truck to unload is 0.3. Due to rains the mean service time at the hopper is increased by 30%. As a consequence, the expected number of trucks in the queuing system (including the one possibly unloading) becomes

A. 10

B. 12

C. 14

D. 16

Answer: Option A

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