She will be able to fill 3 jars because 4/5=16/20 and 1/4 = 5/20 so 5/20 x 3 = 15/20
My understanding is that when the power is a negative number, move it to the denominator and change it to positive.
In this case, the base is y, the power is -3
y^(-3)=1/(y^3)
Three hundred and six thousandths :)

Lets expand both multiplications first.

Simplify down the right side.

Add 38.25 to both sides.

Subtract 11.22x from both sides.

Divide by -21.42 on both sides. Because we're dividing by a negative, we need to change the inequality direction.

This means, out of the options available, (-2.5, ∞) is the correct answer.