Question

What should be added to $6\frac{3}{5}$ to get 15?

Answer 1

Required number to be added = $15-6\frac{3}{5}$

= $\frac{15}{1}-\frac{33}{5}$

= $\frac{75-33}{5}$ [∵ LCM of 1 and 5 = 5]

= $\frac{42}{5}=8\frac{2}{5}$

Hence, the required number is $8\frac{2}{5}$.