[tex]\begin{gathered} \text{For Rakha:} \\ 1\frac{1}{2}\text{hrs/day for 4days implies that:} \\ \text{She spends: (}\frac{3}{2}\times4)\text{ hrs on studies} \\ \text{Rakha spends }\frac{12}{2}=6\text{hrs on studies} \end{gathered}[/tex][tex]\begin{gathered} \text{For Rakha's brother:} \\ \frac{3}{4}\text{hrs/day for 6days implies that:} \\ He\text{ spends: (}\frac{3}{4}\times6)hrs\text{ on studies} \\ \text{Therefore, He spends }\frac{18}{4}=4.5\text{hrs on studies} \end{gathered}[/tex]
Hence, Rakha spends more time on studies.
