15 is 35% of what number?

Let x be the number we are trying to find.
We know that 15 is 35% of x.

Therefore, we can write the proportion:

15/x = 35/100

To solve this proportion, we can cross-multiply:

35x = 15 * 100

Multiplying 15 by 100 gives us:

35x = 1500

Now, to solve for x, we divide both sides of the equation by 35:

x = 1500/35 ≈ 42.857

So, 15 is approximately 35% of 42.857.