let 100% be 10 units
4u --> boys
6u --> girls
60% of 6u walk home. therefore,
[tex] \frac{60}{100} \times 6 = 3 \frac{3}{5} [/tex]
50% of 4u walk home. therefore,
[tex] \frac{1}{2} \times 4 = 2[/tex]
hence, 2u (boys who walk home) + 3.6u (girls who walk home) = 5.6u
to find percentage,
[tex] \frac{5.6}{10} \times 100 = 55.99999[/tex]
rounding up, it'll be 56% of the students