Después de una inundación, el departamento de bomberos de una ciudad utiliza tres bombas para drenar agua de los sótanos inundados. Las tres bombas pueden drenar toda el agua de un sótano inundado en 6horas, 5 horas y 4 horas respectivamente. Si las encienden simultáneamente ¿en cuánto tiempo logran vaciar el sótano?

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have

the answer would be 0.54

the answer is z7+8/5