Abookstore sells used books at 40% discount off the regular price of the book when it was new. the price of a used book is 18$. what was the regular price of that book when it was new?

The regular price was $30.

Step-by-step explanation:

The bookstore sells used books at 40% discount off the price of new books. This means, after the discount, the price of a used book will be 100% - 40% = 60% of the original price.

Now, if the price of the used book is $18, we know that is is 60% of the price of the book when it was new.

Let us call , the price of the book when it was new, then we know that

(this says that 60% of the original price is $18.)

We solve for and get

The price of the book was $30 when it was new.

the answer will be

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.