OG 11 Q 156

[vineetbatra]

I was solving Q 156 of OG 11 and found the language really twisted. I am not sure if the language is wrong or my understanding. Would appreciate if someone could throw some light

A tank contains 10000 gallons of a solutions that is 5% sodium chloride by volume. If 2500 gallons of water evaporate from the tank, the remain solution will be approx. what percent of sodium chloride.

1.25

3.75

6.25

6.67

11.7

I think the q should be phrased like

A tank contains 10000 gallons of a solutions that HAS 5% sodium chloride by volume. If 2500 gallons of water evaporate from the tank, then sodium chloride should be what % of remain solution.

Any thoughts.

[Ad_Astra_Per_Aspera]

Basically it is saying if the tank contains 10,000 gallons , 5% of which is sodium chloride. so sodium chloride is 500 gallons. Now if 2500 gallons of water evaporates that leaves 500 gallons of sodium chloride in a total of 7500 gallons of the solution.

this can be written as: 500 / 7500 => 1 / 15 .. since 15 is is a multiple of 3 .. value of 1/15 converted to percentage will be a repeating decimal. Only choice D is a repeating decimal - thats your answer.

[ILULA08]

Firtslty, 5%of 10000 gallons= 500gallons Sodium Chloride
Now when 2500 gallons of water evaporate we are left with = 7000 gallons of water
Total Vol of solution left = 7000gallons of water + 500gallons of Sodium Chloride.

% of Sodium Chloride in new solution= (500/7500) *100 =6.67%