Percentages SAT question

The correct answer is $1.8$. It’s given that the regular price of a shirt at a store is $\$11.70$, and the sale price of the shirt is $80\%$ less than the regular price. It follows that the sale price of the shirt is $\$11.70(1-\frac{80}{100})$, or $\$11.70(1-0.8)$, which is equivalent to $\$2.34$. It’s also given that the sale price of the shirt is $30\%$ greater than the store’s cost for the shirt. Let $x$ represent the store’s cost for the shirt. It follows that $2.34=(1+\frac{30}{100})x$, or $2.34=1.3x$. Dividing both sides of this equation by $1.3$ yields $x=1.80$. Therefore, the store’s cost, in dollars, for the shirt is $1.80$. Note that 1.8 and 9/5 are examples of ways to enter a correct answer.