RQ × RP = RS × RT
9 × ( 9 + 13 ) = 11 × RT
9 × 22 = 11 × RT
Divide sides by 11
9 × 22 / 11 = 11 × RT / 11
Simplification
9 × 2 = RT
RT = 18
B) 12 inches would be the most accurate measurement.
Since the ruler is exactly 1 foot long, the most accurate measurement is 12 inches. 12.005 is a tempting answer, since it is the most specific/exact, but 12 inches is the most accurate, since this is equal to exactly one foot.
First 8.58
Second 8.508
Third 7.5
Fourth 7.058