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.