Simplify the following expression? 40% of ( 244 x ? ) = 48

We know that 

$40\% = \frac{40}{100} = \frac{2}{5}\Rightarrow \frac{2}{5} x \frac{24}{4} x ? = 48? = \frac{48 x 5 x 4}{2 x 24} = 20$