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?

56 pencils and pens

Step-by-step 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.

8+10

step-by-step explanation:

you multiply 4 by 2 and 5 by 2

30.5*10=350$

you have to multiply the number without the decimal point then add it later but if its tenn u must move the place value of the decimal point 1 to the right.