We can use statement 2 to find the value of her hourly wage given by the equation $1.50 = 0.2x$. This gives us $x=7.50$. We are already given that she works 30 hours, and we can use that to calculate her weekly wages which again comes out to $\$225$. From there the rest of the argument is same as in statement 1. I hope this makes sense.
2 does not give us that her gross weekly pay is 225 so how can you compute without knowing the total weekly pay?
We can use statement 2 to find the value of her hourly wage given by the equation $1.50 = 0.2x$. This gives us $x=7.50$. We are already given that she works 30 hours, and we can use that to calculate her weekly wages which again comes out to $\$225$. From there the rest of the argument is same as in statement 1. I hope this makes sense.