Respuesta :

Blurryface25
1/3÷1/2=2/3
2/3×21/4=7/2
it will take her 3.5 hours
21/4 * 1/3  /  1/2
= 21/12  / 1/2
= 21/12 * 2
= 21/6
= 3 3/6
= 3 1/2