Percentage and Numbers

Question

There are 100 items in a garage sale. 3o% of the items are sold during the first hour of the sale. If 10 items are sold during the secound hour, what persent of the items have not been sold?

Answer 1

The first step is to make sure you understand the question at hand and always start with the given.

 

Given--> 100 items total in the garage sale

        -->30 percent is sold in first hour. Converting percentage to decimal is something to remember for this part.

        --> 10 items are sold in the second hour. 

        --> ? wants to know how many items are not sold, meaning left.

Step 2: Make a plan of what you need to do when starting to solve the problem.

So for our situation, we need to first convert the percent into a decimal format. If you have percent, you move the decimal space two places to the left. If decimal, just move decimal places to the right twice. So in our situation, 30% = 30.00 % = .30 in decimal format.

Next we need to understand that percent is a part of a whole. So you take the total amount, and then you multiply by the percent in decimal form. This will give you how many items were sold in the first hour.

 

100*.30= 30 items were sold in first hour. The question tells us ten more were sold in second hour. so 30+10= 40 items sold so far. so take total and subtract to get leftover items.

 

100-40= 60 items left.

 

Now we make that part into a percent. So part over total and then times a 100.

 

(60/100)*100= 60% of items left. 

 

Answer 2

30 % of 100 items sold is 30 items. Then 10 more items are sold, making total of 40 items sold in first 2 hours. This leaves 100 - 40 = 60 items not sold. So, the percentage of items not sold is: (60 / 100) x 100 = 60%.