By how much percent is four-fifths of 70 lesser than five-sevenths of 112 ?

Answer: Option B

$$\frac{4}{5}$$ × 70 = 56 and $$\frac{5}{7}$$ × 112 = 80
∴ Required percentage :
$$\begin{array}{rl}& =\left(\frac{80-56}{80}\times 100\right)\%\\ & =\left(\frac{24}{80}\times 100\right)\%\\ & =30\%\end{array}$$