Question 13The average of $\frac56,\frac78,\frac7{13},\frac{11}{17}$ is A. In exactly one fraction, interchange the numerator and denominator, giving a new average B. What is the greatest possible value of B − A?$\frac{42}{187}$$\frac{30}{91}$$\frac{15}{224}$$\frac{11}{120}$None of the above