Bunuel wrote:

For how many days are rations expected to last in a camp of 100 soldiers? Assume that each soldier consumes equal quantities of rations per day.

(1) If 100 additional soldiers join the camp after 13 days, each consuming the same quantity of ration as the initial soldiers, the rations would last another 12 days.

(2) If 20 soldiers leave the camp in the very beginning, the rations would last for 25 percent more number of days.

Let the consumption rate per soldier be 1 unit of ration per day.

Hence 100 soldiers will consume 100 units of ration per day.

Let n be the # of days the ration can last for 100 soldiers. Hence Total ration for 100 soldiers is 100n

Statement 1: For 13 days ration consumed by 100 soldiers is 13*100 = 1300 units

Remaining ration = 100n - 1300

100 additional soldiers, along with 100 original consume the remaining ration in 12 days.

Hence 200*12 = 100n -1300

n = 27

Statement 1 is Sufficient.

Statement 2: 20 soldiers leave the camp at the beginning. Hence only 80 soldiers left to consumer 100n units of ration.

80 soldiers consume 80 units per day, therefore # of days the ration lasts for them = 100n/80 =5n/4 days

the # of days given is 25% more, which is 1.25n = 5n/4 days

we get same information, No additional information provided.

Statement 2 is Not Sufficient.

Answer A.

Thanks,

GyM

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