Toni can carry up to 18 lb in her backpack. her lunch weigh 1 lb, her gym clothes weigh 2lb and her books weigh 3lb each. how many books can she carry in her backpack?

Hey there!

Since there will likely only be one lunch and one set of gym clothes, we can simply add those two weights together and subtract them from the total amount of weight Toni can carry. 

18 – (1 + 2) = 18 – 3 = 15

Now, just divide the remaining amount of weight available by three. The answer will be how many books she can carry. 

15 ÷ 3 = 5

Toni can carry her lunch, her clothes, and 5 books in her backpack. 

Hope this helped you out! :-)

So firstly you have to subtract 3lbs because because of her lunch 1lb and gym clothes 2lbs.
When you subtract that you have 15lbs
Now you know that you can't exceed 15lbs, you can divide 15lbs by 3lbs (because each book is 3lbs). which equals 5
So 5 books is how many she can carry in her bag