Marissa plans to use 50 sheets of paper for a scrapbook. how much thicker will the scrapbook be if she uses heavyweight instead or lightweight paper?

100 sheets of lightweight in thickness is 3/10 in
100 sheets of heavyweight in thickness is 2/5 in.

2/5 = 4/10

[(4/10) - (3/10)] / 2 = ____ inch

is the answer 1/20 if not I am sooo confused.

To find out how much thicker the scrapbook will be if Marissa uses heavyweight instead of lightweight paper, we need to compare the thickness of 50 sheets of paper in each type.

First, let's find the thickness of 50 sheets of lightweight paper. We know that 100 sheets of lightweight paper have a thickness of 3/10 inch. Since 50 sheets is half of 100, the thickness of 50 sheets will be half of 3/10 inch.

50 sheets of lightweight thickness = (1/2) * (3/10) inch
= 3/20 inch

Similarly, let's find the thickness of 50 sheets of heavyweight paper. We know that 100 sheets of heavyweight paper have a thickness of 2/5 inch. Therefore, the thickness of 50 sheets will be half of 2/5 inch.

50 sheets of heavyweight thickness = (1/2) * (2/5) inch
= 1/5 inch

Now, we can find the difference in thickness between the two types of paper by subtracting the thickness of 50 sheets of lightweight paper from the thickness of 50 sheets of heavyweight paper.

Difference in thickness = Thickness of 50 sheets of heavyweight - Thickness of 50 sheets of lightweight
= 1/5 inch - 3/20 inch

To subtract these fractions, we need to make sure they have a common denominator. The least common denominator of 5 and 20 is 20.

Difference in thickness = (4/20) inch - (3/20) inch
= 1/20 inch

Therefore, if Marissa uses heavyweight paper instead of lightweight paper, the scrapbook will be 1/20 inch thicker.