Question number 10, when a certain solid substance melts, its volume increases by one-twelfth. By how much does its volume decrease when it solidifies again? What we know is that the volume in liquid form denoted here by V sub L is greater than the volume in solid form denoted by V sub S by exactly one-twelfth. So here is our equation relating the two volumes and we have that the volume in liquid form is 13-twelfths the volume in solid form. Then solving for V sub S, the volume in solid form is equivalent to supposing that the substance solidifies and what that gives us is the volume in solid form is 13-twelfths the volume in liquid form which we can express as the volume in liquid form as a whole minus one-thirteenth. And so that represents a decrease of one-thirteenth and the answer is D.

solid substance

volume increase

melting

solidifying

volume decrease