What is 90% of a number whose 300% is 60?

Sure, let's solve this step by step:

1. First, we need to find the number whose 300% is 60. We can set up the equation like this: 3 * X = 60, where X is the number we're looking for.

2. To solve for X, we divide both sides of the equation by 3: X = 60 / 3.

3. This gives us X = 20.

4. Now that we know X, we can find 90% of it. We set up the equation like this: 0.9 * X = Y, where Y is the number we're looking for.

5. Substituting X = 20 into the equation gives us: 0.9 * 20 = Y.

6. This gives us Y = 18.

So, 90% of the number whose 300% is 60 is 18.