Correct Answer - Option 4 : 13.5%

GIVEN:

Initial solution = 18 l

Water evaporated = 6 l

Sugar % = 9%

CONCEPT:

When the solution is boiled only water evaporates and the amount of sugar remains the same.

CALCULATION:

Amount of sugar,

9% of 18 = 1.62

After evaporation,

Remaining solution = 18 - 6 = 12 l

% of sugar in remaining solution,

⇒ 1.62/12 × 100

= 13.5%