Simplify the following expression.
$$11 \frac{1}{4}÷3\frac{ 3}{5}× 6 \frac{2}{3}+\frac{1}{6}=$$​_____________.

Correct option is B

Solution:

$$11 \frac{1}{4}÷3\frac{ 3}{5}× 6 \frac{2}{3}+\frac{1}{6}$$   

= $$11 \frac{1}{4}÷3\frac{ 3}{5}× 6 \frac{2}{3}+\frac{1}{6}$$  

 $$= 11 \frac{1}{4}÷3\frac{ 3}{5}× 6 \frac{2}{3}+\frac{1}{6} \\\ \\= \frac{45}{4} \times \frac{5}{18} \times \frac{20}{3} + \frac{1}{6}$$  

 = $$\frac{125}{6}+ \frac{1}{6}$$  

= $$\frac{126}{6}$$ 

= 21