Respuesta :
30% of what is 9...
0.30x = 9
x = 9 / 0.30
x = 30...so its 30 minutes total time
and she has already used 9....so she has (30 - 9) = 21 minutes left
0.30x = 9
x = 9 / 0.30
x = 30...so its 30 minutes total time
and she has already used 9....so she has (30 - 9) = 21 minutes left