Caroline can sketch 3 cartoon strips in five hours. How long will it take her to sketch 12 strips

Answer 1

The first step for this problem is to create a proportion. A proportion basically means that two ratios are equal. (Ratios are fractions if that makes it easier). If you do not know the other part of the ratio/fraction or also known as an unknown variable, a X or another variable will sit in its place.

To set up a proportion for this problem with one variable unknown it will look like this

3 = 12

5 x

The next step is to cross multiply. That basically means diagonally multiply across the equation. (It will look like a big X).

In this problem the 3 and the X would multiply and the 12 and the 5 would multiply. Remember it will look like an X over the problem.

After multiplying the equation will look like this

3x = 60

Now we have to get X alone to figure out the ratio. To do this we divide off the 3 to get X alone, but we have to remember to keep the equation balanced so this will have to be done to both sides. So after dividing 3 from X we will have to divide 3 from 60

This looks like this

3x = 60

3 3

After dividing 3 from X the X will be alone. Next is dividing 3 from 60. After doing the division 60/3 is 20. Now that x is alone and 60 is divided by 3 the equation is done! Now its time to interpret it.

So the equation now looks like this

x = 20

So the ratios is now figured out and 20 will now replace the X in the original proportion equation

It now looks like this

3 = 12

5 20

Now its time to interpret- If Caroline could draw 3 sketches in 5 hours, she can then draw 12 sketches in how many hours? Well time to look at the finished ratio- it shows that 12 sketches can be done in 20 hours!

So what is the answer- Caroline can draw 12 sketches in 20 hours!

Hopefully this helps!