Question

The ratio of pencils to pens is 3 to 5. There are 21 pencils in the classroom. How

many total pens and pencils are in the classroom?

Answer 1

56 pencils and pens

Explanation:

3:5 is the ratio, and then put that into a fraction and then make a proportion

3/5=21/x

eCross multiply and divide so do 21*5 divided by 3. This gives us an answer of 35. Now we know we have 35 pens. 35+21, adding the pen and pencil, is 56. You can always also look for relationships, so if you could see that multiplying 7 gives you the answer, than do that to the 5, and then add it together.